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  • On HP Mini, unable to select 800x600 resolution

    - by Roboto
    I have an HP Mini laptop. I can only make resolution setting for my display of 1024x576. The HP Deskjet 6988 driver only allows resolution settings of 800x600. I don't care how 800x600 would look on my laptop, I only want to install the driver for the printer and set it back. I went into the registry, but it was showing a resolution setting of 800x600. How else can I set the resolution or at least add the option in my Display Properties for 800x600?

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  • Linux filesystem suggestion for MySQL with a 100% SELECT workload

    - by gmemon
    I have a MySQL database that contains millions of rows per table and there are 9 tables in total. The database is fully populated, and all I am doing is reads i.e., there are no INSERTs or UPDATEs. Data is stored in MyISAM tables. Given this scenario, which linux file system would work best? Currently, I have xfs. But, I read somewhere that xfs has horrible read performance. Is that true? Should I shift the database to an ext3 file system? Thanks

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • How to autosum value on dropdown and radio select

    - by Wilf
    I'm working on an auto calculation form which is a total column will change after a radio and a dropdown is clicked. I can make the total change for both dropdowns but the problem occurs when I tried to add a radio option. Here is my code. HTML Ages 10+: <select id="Adult" name="Adult"> <option selected="selected" value="0">0</option> <option value="1">1</option> <option value="2">2</option> <option value="3">3</option> <option value="4">4</option> <option value="5">5</option> <option value="6">6</option> <option value="7">7</option> <option value="8">8</option> <option value="9">9</option> </select> <br />Ages 3-9: <select id="Child" name="Child"> <option selected="selected" value="0">0</option> <option value="1">1</option> <option value="2">2</option> <option value="3">3</option> <option value="4">4</option> <option value="5">5</option> <option value="6">6</option> <option value="7">7</option> <option value="8">8</option> <option value="9">9</option> </select> <br />Food <input type="radio" name="food" id="food0" value="0" /> <label for="food0">No</label> <input type="radio" name="food" id="food1" value="10" /> <label for="food1">Yes</label> <table width="100%" border="1" align="center"> <tr> <td>Product</td> <td>Ages 10+</td> <td>Ages 3-9</td> <td>Food</td> <td>Price</td> </tr> <tr> <td>2 Day Ticket</td> <td>$235.00</td> <td>$223.00</td> <td><span id="food">0</span> </td> <td>$<span class="amount" id="2DayTotal"></span> </td> </tr> <tr> <td>3 Day Ticket</td> <td>$301.00</td> <td>$285.00</td> <td><span id="food">0</span> </td> <td>$<span class="amount" id="3DayTotal"></span> </td> </tr> <tr> <td>4 Day Ticket</td> <td>$315.00</td> <td>$298.00</td> <td><span id="food">0</span> </td> <td>$<span class="amount" id="4DayTotal"></span> </td> </tr> <tr> <td>5 Day Ticket</td> <td>$328.00</td> <td>$309.00</td> <td><span id="food">0</span> </td> <td>$<span class="amount" id="5DayTotal"></span> </td> </tr> </table> JavaScript var numAdult = 0; var numChild = 0; $("#Adult").change(function () { numAdult = $("#Adult").val(); calcTotals(); }); $("#Child").change(function () { numChild = $("#Child").val(); calcTotals(); }); $('input[type=radio]').change(function(evt) { $('#food').html($(this).val()); }); function calcTotals() { $("#2DayTotal").text(235 * numAdult + 223 * numChild); $("#3DayTotal").text(301 * numAdult + 285 * numChild); $("#4DayTotal").text(315 * numAdult + 298 * numChild); $("#5DayTotal").text(328 * numAdult + 309 * numChild); } The issues are: I'd like the food column change to it's value when a radio is click. It works only the first id. After a radio is clicked. A fumction calcTotals() is called to sum an additional food cost. Demo here : http://jsfiddle.net/4Jegn/178/ Please be advice.

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  • INNER JOIN syntax for mySQL using phpmyadmin

    - by David van Dugteren
    SELECT Question.userid, user.uid FROM `question` WHERE NOT `userid`=2 LIMIT 0, 60 INNER JOIN `user` ON `question`.userid=`user`.uid ORDER BY `question`.userid returns Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'INNER JOIN User ON question.userid=user.uid ORDER BY question.userid' at line 5 Can't for the life of me figure out what I'm doing wrong here.

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  • PHP form values after POST in dropdown

    - by FFish
    I have a form with 'selected' values pulled from the database. Now I want the user to edit the values. When the data is send I want to show the new values. When I submit my form I always get the 'green' value? What am I doing wrong here? <?php // pulled from db $color = "blue"; // update if (isset($_POST['Submit'])) { echo "write to db: " . $_POST['name'] . " + " . $_POST['color']; } ?> <html> <form name="form1" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> <label for="name">Name:</label> <input type="text" name="name" size="30" value="<?php echo (isset($_POST['name'])) ? $_POST['name'] : ""; ?>"> <br /> <label for="color">Color:</label> <select name="color"> <option <?php echo (isset($_POST['color']) || $color == "red") ? 'selected="selected"' : ''; ?> value="red">red</option> <option <?php echo (isset($_POST['color']) || $color == "blue") ? 'selected="selected"' : ''; ?> value="blue">blue</option> <option <?php echo (isset($_POST['color']) || $color == "green") ? 'selected="selected"' : ''; ?> value="green">green</option> </select> <br /> <input type="submit" name="Submit" value="Update"> </form> </html>

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  • Nesting, grouping Sqlite syntax?

    - by Linda
    I can't for the life of me figure out this Sqlite syntax. Our database contains records like: TX, Austin OH, Columbus OH, Columbus TX, Austin OH, Cleveland OH, Dayton OH, Columbus TX, Dallas TX, Houston TX, Austin (State-field and a city-field.) I need output like this: OH: Columbus, Cleveland, Dayton TX: Dallas, Houston, Austin (Each state listed once... and all the cities in that state.) What would the SELECT statement(s) look like?

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  • Count times ID appears in a table and return in row.

    - by Tyler
    SELECT Boats.id, Boats.date, Boats.section, Boats.raft, river_company.company, river_section.section AS river FROM Boats INNER JOIN river_company ON Boats.raft = river_company.id INNER JOIN river_section ON Boats.section = river_section.id ORDER BY Boats.date DESC, river, river_company.company Returns everything I need. But how would I add a [Photos] table and count how many times Boats.id occurs in it and add that to the returned rows. So if there are 5 photos for boat #17 I want the record for boat #17 to say PhotoCount = 5

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  • Select number of rows for each group where two column values makes one group

    - by Fábio Antunes
    I have a two select statements joined by UNION ALL. In the first statement a where clause gathers only rows that have been shown previously to the user. The second statement gathers all rows that haven't been shown to the user, therefore I end up with the viewed results first and non-viewed results after. Of course this could simply be achieved with the same select statement using a simple ORDER BY, however the reason for two separate selects is simple after you realize what I hope to accomplish. Consider the following structure and data. +----+------+-----+--------+------+ | id | from | to | viewed | data | +----+------+-----+--------+------+ | 1 | 1 | 10 | true | .... | | 2 | 10 | 1 | true | .... | | 3 | 1 | 10 | true | .... | | 4 | 6 | 8 | true | .... | | 5 | 1 | 10 | true | .... | | 6 | 10 | 1 | true | .... | | 7 | 8 | 6 | true | .... | | 8 | 10 | 1 | true | .... | | 9 | 6 | 8 | true | .... | | 10 | 2 | 3 | true | .... | | 11 | 1 | 10 | true | .... | | 12 | 8 | 6 | true | .... | | 13 | 10 | 1 | false | .... | | 14 | 1 | 10 | false | .... | | 15 | 6 | 8 | false | .... | | 16 | 10 | 1 | false | .... | | 17 | 8 | 6 | false | .... | | 18 | 3 | 2 | false | .... | +----+------+-----+--------+------+ Basically I wish all non viewed rows to be selected by the statement, that is accomplished by checking weather the viewed column is true or false, pretty simple and straightforward, nothing to worry here. However when it comes to the rows already viewed, meaning the column viewed is TRUE, for those records I only want 3 rows to be returned for each group. The appropriate result in this instance should be the 3 most recent rows of each group. +----+------+-----+--------+------+ | id | from | to | viewed | data | +----+------+-----+--------+------+ | 6 | 10 | 1 | true | .... | | 7 | 8 | 6 | true | .... | | 8 | 10 | 1 | true | .... | | 9 | 6 | 8 | true | .... | | 10 | 2 | 3 | true | .... | | 11 | 1 | 10 | true | .... | | 12 | 8 | 6 | true | .... | +----+------+-----+--------+------+ As you see from the ideal result set we have three groups. Therefore the desired query for the viewed results should show a maximum of 3 rows for each grouping it finds. In this case these groupings were 10 with 1 and 8 with 6, both which had three rows to be shown, while the other group 2 with 3 only had one row to be shown. Please note that where from = x and to = y, makes the same grouping as if it was from = y and to = x. Therefore considering the first grouping (10 with 1), from = 10 and to = 1 is the same group if it was from = 1 and to = 10. However there are plenty of groups in the whole table that I only wish the 3 most recent of each to be returned in the select statement, and thats my problem, I not sure how that can be accomplished in the most efficient way possible considering the table will have hundreds if not thousands of records at some point. Thanks for your help. Note: The columns id, from, to and viewed are indexed, that should help with performance. PS: I'm unsure on how to name this question exactly, if you have a better idea, be my guest and edit the title.

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  • Create a flexible, localized, Ruby-on-Rails list-of-values

    - by Craig
    I have a list of values (Beginner, Intermediate, Advanced, Fluent, Native) that I would like to: act as the model for a SELECT list act as a model to convert ids to values in a HTML table use in multiple controllers and views keep in an order that preserves the business rules (ordered by skill level) localize at some point in the future Is there a way of implementing this list to address all or most of my needs?

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  • Is is possible to use IOCP (or other API) in reactor stle operations?

    - by Artyom
    Hello, Is there any scalable Win32 API (like IOCP not like select) that gives you reactor style operations on sockets? AFAIK IOCP allows you to receive notification on completed operations like data read or written (proactor) but I'm looking for reactor style of operations: I need to get notification when the socket is readable or writable (reactor). Something similar to epoll, kqueue, /dev/poll ? Is there such API in Win32? If so where can I find a manual on it?

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  • linq selecting into custom object

    - by user276640
    what is wrong with such code public List<SearchItem> Search(string find) { return (from i in _dataContext.News where i.Text.Contains(find) select new SearchItem { ControllerAction = "test", id = i.Id.ToString(), LinkText = "test" }).ToList(); } public struct SearchItem { public string ControllerAction; public string LinkText; public string id; }

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  • Sql query to get this result..

    - by bala3569
    Consider i have a user table and i have three columns mobilePhone,homePhone and workPhone... I have to select homePhone for every user as first pref if there is no value i ll go for mobilePhone and if there is no value for it i ll go for workPhone.... Any suggestion how it can be done in mysql..

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  • Datagridview error

    - by Simon
    I have two datagridviews. So for the second one, i just copy-pasted the code from the first and changed where the difference was. But i get an error at the secod data grid when i want to view the result of my sql code. Translated in english the error show something like that there was no value given to at least one required parameter. Please help! private void button1_Click(object sender, EventArgs e) { string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=save.mdb"; try { database = new OleDbConnection(connectionString); database.Open(); date = DateTime.Now.ToShortDateString(); string queryString = "SELECT zivila.naziv,(obroki_save.skupaj_kalorij/zivila.kalorij)*100 as Kolicina_v_gramih " + "FROM (users LEFT JOIN obroki_save ON obroki_save.ID_uporabnika=users.ID)" + " LEFT JOIN zivila ON zivila.ID=obroki_save.ID_zivila " + " WHERE users.ID= " + a.ToString(); loadDataGrid(queryString); } catch (Exception ex) { MessageBox.Show(ex.Message); return; } } public void loadDataGrid(string sqlQueryString) { OleDbCommand SQLQuery = new OleDbCommand(); DataTable data = null; dataGridView1.DataSource = null; SQLQuery.Connection = null; OleDbDataAdapter dataAdapter = null; dataGridView1.Columns.Clear(); // <-- clear columns SQLQuery.CommandText = sqlQueryString; SQLQuery.Connection = database; data = new DataTable(); dataAdapter = new OleDbDataAdapter(SQLQuery); dataAdapter.Fill(data); dataGridView1.DataSource = data; dataGridView1.AllowUserToAddRows = false; dataGridView1.ReadOnly = true; dataGridView1.Columns[0].Visible = true; } private void Form8_Load(object sender, EventArgs e) { } private void button2_Click(object sender, EventArgs e) { string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=save.mdb"; try { database = new OleDbConnection(connectionString); database.Open(); date = DateTime.Now.ToShortDateString(); string queryString = "SELECT skupaj_kalorij " + "FROM obroki_save " + " WHERE users.ID= " + a.ToString(); loadDataGrid2(queryString); } catch (Exception ex) { MessageBox.Show(ex.Message); return; } } public void loadDataGrid2(string sqlQueryString) { OleDbCommand SQLQuery = new OleDbCommand(); DataTable data = null; dataGridView2.DataSource = null; SQLQuery.Connection = null; OleDbDataAdapter dataAdapter = null; dataGridView2.Columns.Clear(); // <-- clear columns SQLQuery.CommandText = sqlQueryString; SQLQuery.Connection = database; data = new DataTable(); dataAdapter = new OleDbDataAdapter(SQLQuery); dataAdapter.Fill(data); dataGridView2.DataSource = data; dataGridView2.AllowUserToAddRows = false; dataGridView2.ReadOnly = true; dataGridView2.Columns[0].Visible = true; }

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  • help translate this week query from Oracle PL/SQL to SQL Server 2008

    - by Sarah Vessels
    I have the following query that runs in my Oracle database and I want to have the equivalent for a SQL Server 2008 database: SELECT TRUNC( /* Midnight Sunday */ NEXT_DAY(SYSDATE, 'SUN') - (7*LEVEL) ) AS week_start, TRUNC( /* 23:59:59 Saturday */ NEXT_DAY(NEXT_DAY(SYSDATE, 'SUN') - (7*LEVEL), 'SAT') + 1 ) - (1/(60*24)) + (59/(60*60*24)) AS week_end FROM DUAL CONNECT BY LEVEL <= 4 /* Get the past 4 weeks */ What the query does is get the start of the week and the end of the week for the last 4 weeks. It generates data like the following: WEEK_START WEEK_END 2010-03-07 00:00:00 2010-03-13 23:59:59 2010-02-28 00:00:00 2010-03-06 23:59:59 ...

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  • Php, mysql selection

    - by cosy
    I have this table ATTRIBUTE id name um 12 capacity MB;GB;TB And this table2 : id id_attribute id_product name value um 1 12 40 hdd maxtor 30 GB 2 12 41 hdd maxtor 40 GB 3 12 42 hdd y 1 TB How can i select from table2 in this order : 30GB 40GB 1TB? Thanks a lot!

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  • using union in a construct sparql query

    - by simon
    hello, i have such a sparql query: select ?s ?p ?o from <http://localhost:8890/DAV/ranking> where { {<http://seekda.com/providers/cdyne.com/PhoneNotify> so:hasEndpoint ?s. ?s ?p ?o} union {<http://seekda.com/providers/cdyne.com/PhoneNotify> ?p ?o} } but i need a graph query (construct ord describe). unfortunatly i have no clue about how to use unions in construct or describe queries. please help me best regards simon

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  • Customized combobox text in HTML / JavaScript

    - by rybz
    Hi, I wonder if it is possible to create combo box as in the picture below. The aim is that the actual text of the combo (select in HTML) would be different that items' texts that are displayed while the combo is opened. The application is written using Google Web Toolkit so any solution in gwt or HTML/JavaScript would be great. Thanks for any hints.

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  • MySQL database query returns empty result

    - by user1791096
    I am doing a data migration and getting empty result of simple query with one join. Following is the query Select * from users u INNER JOIN temp_users tu ON tu.uid = u.uid There hundreds of records which have same uid in both tables, but this query returns only one record. Following is the structure of tables users table uid: varchar(50) utf8_general_ci Yes NULL temp_users table uid: varchar(50) utf8_general_ci Yes NULL Is there anyone who faced same problem?

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