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  • SQLITE problem in rowid

    - by Saurabh
    I am using SQLite C# library and as per my requirement, before going to add I am retreving the rowid of that table. It is working fine but hetting error when table is empty. Once we add any data(a row) then it’s working fine . mDbCon = GetConnection(); SQLiteCommand cmd = mDbCon.CreateCommand(); cmd.CommandText = " SELECT MAX(rowid) FROM " + “MYTABLE”; cmd.CommandType = CommandType.Text; mDbCon.Open(); SQLiteDataReader sqReader = cmd.ExecuteReader(); while (sqReader.Read()) { if ( sqReader.IsDBNull(0) ) { max = (Int32)sqReader.GetInt32(0); } } mDbCon.Close(); It’s throwing exception when table “MYTABLE” don’t have any data.

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  • sqlite on iphone can open db but not prepare statements

    - by jan
    I'm brand new to using sqlite so I may have missed something basic. I've created a database and copied it into my app's document's directory. I'm able to open it but when I make a call to sqlite3_prepare_v2 I receive SQLITE_ERROR, "SQL error or missing database". here's my code: sqlite3 *database; if(sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) { sqlite3_stmt *compiledStatement; NSString *sqlStatement = @"select * from dbname"; int result = sqlite3_prepare_v2(database, [sqlStatement UTF8String], -1, &compiledStatement, nil); ... } the same sql statement works in the terminal. I've found this question in a few places either without answers or with solutions that don't fix my problem. I'm hoping someone here will be able to help. Thanks.

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  • Declaring data types in SQLite

    - by dan04
    I'm familiar with how type affinity works in SQLite: You can declare column types as anything you want, and all that matters is whether the type name contains "INT", "CHAR", "FLOA", etc. But is there a commonly-used convention on what type names to use? For example, if you have an integer column, is it better to distinguish between TINYINT, SMALLINT, MEDIUMINT, and BIGINT, or just declare everything as INTEGER? So far, I've been using the following: INTEGER REAL CHAR(n) -- for strings with a known fixed with VARCHAR(n) -- for strings with a known maximum width TEXT -- for all other strings BLOB BOOLEAN DATE -- string in "YYYY-MM-DD" format TIME -- string in "HH:MM:SS" format TIMESTAMP -- string in "YYYY-MM-DD HH:MM:SS" format (Note that the last three are contrary to the type affinity.)

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  • mysql, sqlite database source code

    - by Yang
    hi guys, i know implementing database is a huge topic, but i want to have a basic understanding of how database systems works (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database, since there are a few already proven very robust open source databases like mysql, sqlite and so on. however, the code are very complicated and i have no clue where to start. also i find that the old school database textbooks are only explaining the theory, not the implementation details. Can anyone suggest how should i get started and is there any books that emphasis on the technology and techniques of building dbms used in modern database industry? Thank in advance!

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  • Trying to speed up a SQLITE UNION QUERY

    - by user142683
    I have the below SQLITE code SELECT x.t, CASE WHEN S.Status='A' AND M.Nomorebets=0 THEN S.PriceText ELSE '-' END AS Show_Price FROM sb_Market M LEFT OUTER JOIN (select 2010 t union select 2020 t union select 2030 t union select 2040 t union select 2050 t union select 2060 t union select 2070 t ) as x LEFT OUTER JOIN sb_Selection S ON S.MeetingId=M.MeetingId AND S.EventId=M.EventId AND S.MarketId=M.MarketId AND x.t=S.team WHERE M.meetingid=8051 AND M.eventid=3 AND M.Name='Correct Score' With the current interface restrictions, I have to use the above code to ensure that if one selection is missing, that a '-' appears. Some feed would be something like the following SelectionId Name Team Status PriceText =================================== 1 Barney 2010 A 10 2 Jim 2020 A 5 3 Matt 2030 A 6 4 John 2040 A 8 5 Paul 2050 A 15/2 6 Frank 2060 S 10/11 7 Tom 2070 A 15 Is using the above SQL code the quickest & efficient?? Please advise of anything that could help. Messages with updates would be preferable.

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  • SQLite - a smart way to remove and add new objects

    - by Ilya
    Hi, I have a table in my database and I want for each row in my table to have an unique id and to have the rows named sequently. For example: I have 10 rows, each has an id - starting from 0, ending at 9. When I remove a row from a table, lets say - row number 5, there occurs a "hole". And afterwards I add more data, but the "hole" is still there. It is important for me to know exact number of rows and to have at every row data in order to access my table arbitrarily. There is a way in sqlite to do it? Or do I have to manually manage removing and adding of data? Thank you in advance, Ilya.

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  • [C#] SQLite - Creating and changing databases on the fly

    - by Oskar Kjellin
    Today I use SQLite and send a database-file with the project. However I want the database to be created when the user first starts the software. Is there a way to copy the code needed to create a database based on the existing database? The problem is that when a user downloads a new version he might be tricked into copying over his last database and lose the data. I'd like a nice way to check the version of the database and modify it if I need new columns or tables etc. Or, if it does not exist at all, create a new database? I know I can probably make create the code to make the database from the beginning but I want it to be based on the existing database I have created by a gui.

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  • Eager loading vs. many queries with PHP, SQLite

    - by Mike
    I have an application that has an n+1 query problem, but when I implemented a way to load the data eagerly, I found absolutely no performance gain. I do use an identity map, so objects are only created once. Here's a benchmark of ~3000 objects. first query + first object creation: 0.00636100769043 sec. memory usage: 190008 bytes iterate through all objects (queries + objects creation): 1.98003697395 sec. memory usage: 7717116 bytes And here's one when I use eager loading. query: 0.0881109237671 sec. memory usage: 6948004 bytes object creation: 1.91053009033 sec. memory usage: 12650368 bytes iterate through all objects: 1.96605396271 sec. memory usage: 12686836 bytes So my questions are Is SQLite just magically lightning fast when it comes to small queries? (I'm used to working with MySQL.) Does this just seem wrong to anyone? Shouldn't eager loading have given much better performance?

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  • Slow SQLite access on iPhone

    - by georgij
    I have a quite slow data retrieval from a sqlite database on my iPhone and perhaps someone have an alternative idea to explain this. From what I tracked down so far sqlite3_step(statement) is sometimes unusually slow. While retrieving e.g. 50 rows from the database to execute this step takes normally some milliseconds but sometimes it takes several seconds. My database is not small (80MB) and my theory is that the reason is paging. But can someone else think of an other reason for this?

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  • How to transfer SQLite db to web server

    - by Shane
    Hi, I have an application that creates an SQLite database and saves information to it over the course of a day. At the end of the day i want to export this database to a web server. Could anyone point me in the right direction for this? Should I use httppost or put. I have researched this myself online but there seems to be so many different ways to explore. The server side does not exist yet either. I have access to an apache server so i am hoping to use that. Could anyone advise me the best/most simple way to do this? Thanks

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  • sqlite with Perl for Windows; suitable for relocation

    - by Paul Nathan
    I need to set up sqllite for Perl on a Windows box. However - Perl is probably being run over the network from a central server, and I do not know what modules will be available on initial running of my script. I can guarantee Perl 5.8+ (activestate) or Perl 5.10+ (strawberry). Therefore, I need to package sqlite & the associated Perl module(s) in the project directory itself. Having Goggled around, I don't see any immediate zipfile to do this.

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  • SQLite Modify Column

    - by Nathan
    I need to modify a column in a SQLite database but I have to do it programatically due to the database already being in production. From my research I have found that in order to do this I must do the following. Create a new table with new schema Copy data from old table to new table Drop old table Rename new table to old tables name That seems like a ridiculous amount of work for something that should be relatively easy. Is there not an easier way? All I need to do is change a constraint on a existing column and give it a default value.

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  • Next step for Python app using Sqlite db

    - by ChrisC
    I want to write a db program in Python using Sqlite. I have the db table structure planned, and am ready to move to the next step, which I think is to work any bugs out of the db structure. I am totally inexperienced in development except for writing the original db (written in MS Access), and an Intro to C++ class (OOP concepts and console C++ programs). Is it time to test the db structure? If so, what's the best way, and what tool(s) should I use? Thank you.

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  • creating a Menu from SQLite values in Java

    - by shanahobo86
    I am trying to create a ListMenu using data from an SQLite database to define the name of each MenuItem. So in a class called menu.java I have defined the array String classes [] = {}; which should hold each menu item name. In a DBAdapter class I created a function so the user can insert info to a table (This all works fine btw). public long insertContact(String name, String code, String location, String comments, int days, int start, int end, String type) { ContentValues initialValues = new ContentValues(); initialValues.put(KEY_NAME, name); initialValues.put(KEY_CODE, code); initialValues.put(KEY_LOCATION, location); initialValues.put(KEY_COMMENTS, comments); initialValues.put(KEY_DAYS, days); initialValues.put(KEY_START, start); initialValues.put(KEY_END, end); initialValues.put(KEY_TYPE, type); return db.insert(DATABASE_TABLE, null, initialValues); } It would be the Strings inserted into KEY_NAME that I need to populate that String array with. Does anyone know if this is possible? Thanks so much for the help guys. If I implement that function by Sam/Mango the program crashes, am I using it incorrectly or is the error due to the unknown size of the array? DBAdapter db = new DBAdapter(this); String classes [] = db.getClasses(); edit: I should mention that if I manually define the array: String classes [] = {"test1", "test2", "test3", etc}; It works fine. The error is a NullPointerException Here's the logcat (sorry about the formatting). I hadn't initialized with db = helper.getReadableDatabase(); in the getClasses() function but unfortunately it didn't fix the problem. 11-11 22:53:39.117: D/dalvikvm(17856): Late-enabling CheckJNI 11-11 22:53:39.297: D/TextLayoutCache(17856): Using debug level: 0 - Debug Enabled: 0 11-11 22:53:39.337: D/libEGL(17856): loaded /system/lib/egl/libGLES_android.so 11-11 22:53:39.337: D/libEGL(17856): loaded /system/lib/egl/libEGL_adreno200.so 11-11 22:53:39.357: D/libEGL(17856): loaded /system/lib/egl/libGLESv1_CM_adreno200.so 11-11 22:53:39.357: D/libEGL(17856): loaded /system/lib/egl/libGLESv2_adreno200.so 11-11 22:53:39.387: I/Adreno200-EGLSUB(17856): <ConfigWindowMatch:2078>: Format RGBA_8888. 11-11 22:53:39.407: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x5c66d000 size:36593664 offset:32825344 fd:65 11-11 22:53:39.417: E/(17856): Can't open file for reading 11-11 22:53:39.417: E/(17856): Can't open file for reading 11-11 22:53:39.417: D/OpenGLRenderer(17856): Enabling debug mode 0 11-11 22:53:39.477: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x5ecd3000 size:40361984 offset:36593664 fd:68 11-11 22:53:40.507: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x61451000 size:7254016 offset:3485696 fd:71 11-11 22:53:41.077: I/Adreno200-EGLSUB(17856): <ConfigWindowMatch:2078>: Format RGBA_8888. 11-11 22:53:41.077: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x61c4c000 size:7725056 offset:7254016 fd:74 11-11 22:53:41.097: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x623aa000 size:8196096 offset:7725056 fd:80 11-11 22:53:41.937: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x62b7b000 size:8667136 offset:8196096 fd:83 11-11 22:53:41.977: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x61c4c000 size:7725056 offset:7254016 11-11 22:53:41.977: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x623aa000 size:8196096 offset:7725056 11-11 22:53:41.977: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x62b7b000 size:8667136 offset:8196096 11-11 22:53:42.167: I/Adreno200-EGLSUB(17856): <ConfigWindowMatch:2078>: Format RGBA_8888. 11-11 22:53:42.177: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x61c5d000 size:17084416 offset:13316096 fd:74 11-11 22:53:42.317: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x63853000 size:20852736 offset:17084416 fd:80 11-11 22:53:42.357: D/OpenGLRenderer(17856): Flushing caches (mode 0) 11-11 22:53:42.357: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x5c66d000 size:36593664 offset:32825344 11-11 22:53:42.357: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x5ecd3000 size:40361984 offset:36593664 11-11 22:53:42.367: D/memalloc(17856): /dev/pmem: Unmapping buffer base:0x61451000 size:7254016 offset:3485696 11-11 22:53:42.757: D/memalloc(17856): /dev/pmem: Mapped buffer base:0x5c56d000 size:24621056 offset:20852736 fd:65 11-11 22:53:44.247: D/AndroidRuntime(17856): Shutting down VM 11-11 22:53:44.247: W/dalvikvm(17856): threadid=1: thread exiting with uncaught exception (group=0x40ac3210) 11-11 22:53:44.257: E/AndroidRuntime(17856): FATAL EXCEPTION: main 11-11 22:53:44.257: E/AndroidRuntime(17856): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{niall.shannon.timetable/niall.shannon.timetable.menu}: java.lang.NullPointerException 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1891) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread.access$600(ActivityThread.java:127) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.os.Handler.dispatchMessage(Handler.java:99) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.os.Looper.loop(Looper.java:137) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread.main(ActivityThread.java:4441) 11-11 22:53:44.257: E/AndroidRuntime(17856): at java.lang.reflect.Method.invokeNative(Native Method) 11-11 22:53:44.257: E/AndroidRuntime(17856): at java.lang.reflect.Method.invoke(Method.java:511) 11-11 22:53:44.257: E/AndroidRuntime(17856): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823) 11-11 22:53:44.257: E/AndroidRuntime(17856): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590) 11-11 22:53:44.257: E/AndroidRuntime(17856): at dalvik.system.NativeStart.main(Native Method) 11-11 22:53:44.257: E/AndroidRuntime(17856): Caused by: java.lang.NullPointerException 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:221) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:157) 11-11 22:53:44.257: E/AndroidRuntime(17856): at niall.shannon.timetable.DBAdapter.getClasses(DBAdapter.java:151) 11-11 22:53:44.257: E/AndroidRuntime(17856): at niall.shannon.timetable.menu.<init>(menu.java:15) 11-11 22:53:44.257: E/AndroidRuntime(17856): at java.lang.Class.newInstanceImpl(Native Method) 11-11 22:53:44.257: E/AndroidRuntime(17856): at java.lang.Class.newInstance(Class.java:1319) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.Instrumentation.newActivity(Instrumentation.java:1023) 11-11 22:53:44.257: E/AndroidRuntime(17856): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1882) 11-11 22:53:44.257: E/AndroidRuntime(17856): ... 11 more 11-11 22:53:46.527: I/Process(17856): Sending signal. PID: 17856 SIG: 9

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  • Using Flex to keep local SQLite database in sync with live server database

    - by DaveC
    I want to create a Flex 3 application running in Adobe Air that accesses an SQLite database and I need to keep this database in sync with an SQL server 2005 database running a website. Is this something that Flex supports or is it going to be a custom script? Also, has anybody done anything like this? Edit: The synchronisation can be done on a daily basis rather than real time. The data will be read only from a front end perspective with a CMS to do updates on the website.

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  • How to transfer SQLite db to web server on android phone

    - by Shane
    Hi, I have an application that creates an SQLite database and saves information to it over the course of a day. At the end of the day i want to export this database to a web server. Could anyone point me in the right direction for this? Should I use httppost or put. I have researched this myself online but there seems to be so many different ways to explore. The server side does not exist yet either. I have access to an apache server so i am hoping to use that. Could anyone advise me the best/most simple way to do this? Thanks

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  • Android and SQLite using the SQLiteOpenHelper

    - by tunneling
    I have a SQLite database, and several tables within that database. I am developing a DBAdapter for each table within the database. (reference Reto Meier's Professional Android 2 Application Development, Listing 7.1). I am using the adb shell to interface with the database from the command line and see that the database is being populated as I expect. Occasionally, I want to drop a table so that I can ensure it's being built properly, from scratch. The problem is that SQLiteOpenHelper only checks to see if the database exists. Is there a typical solution to writing a helper to also see that the table(s) exists? Basically once I drop a table, the helper checks to see that the database exists and assumes all is well. Also, the CREATE_DATABASE string used in the reference above only creates the one table. Should I consider using the DBAdapter for an adapter to ALL of my tables? That doesn't seem as clean to me. Reference Material

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  • Inserting nil Values into Sqlite Database?

    - by Chris
    I am working on an iPhone App where I am pulling data from an XML file and inserting it into a sqlite database located in the App. I am able to successfully do this process, but it appears that if I try to sqlite3_bind_text with a NSString that has a value of "nil", the App quickly dies. This is an example of code that fails: (modified for this example) // idvar = 1 // valuevar = nil const char *sqlStatement = "insert into mytable (id, value) VALUES(?, ?)"; sqlite3_stmt *compiledStatement = nil; sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL); sqlite3_bind_int(compiledStatement, 1, [idvar intValue]);; sqlite3_bind_text(compiledStatement, 2, [valuevar UTF8String], -1, SQLITE_TRANSIENT);

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  • Inserting multiple types into an SQLite database with Python

    - by mankoff
    I'm trying to create an SQLite 3 database from Python. I have a few types I'd like to insert into each record: A float, and then 3 groups of n floats, currently a tuple but could be an array or list.. I'm not well-enough versed in Python to understand all the differences. My problem is the INSERT statement. DAS = 12345 lats = (42,43,44,45) lons = (10,11,12,13) times = (1,2,3,4,5,6,7,8,9) import sqlite3 connection = sqlite3.connect("test.db") cursor = connection.cursor() cursor.execute( "create table foo(DAS LONG PRIMARY KEY,lats real(4),lons real(4), times real(9) )" ) I'm not sure what comes next. Something along the lines of: cmd = 'INSERT into foo values (?,?,?,?), ..." cursor.execute(cmd) How should I best build the SQL insert command given this data?

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  • Prevent sqlite INJECTION ATTACKS on your own iPhone?

    - by Bonnie
    I always take precautions regarding SQL INJECTION ATTACKS when data is saved between someone's iPhone and a remote database on the cloud. But is it also necessary to do the same... when just saving data (using sqlite) from someone's cell phone, to a database that's just on their own phone? What's the worse they can do? Delete their own data (or tables) on their own phone? (If they really try hard enough.) Thanks.

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  • Dealing w/ Sqlite Join results in a cursor

    - by Bill
    I have a one-many relationship in my local Sqlite db. Pretty basic stuff. When I do my left outer join I get back results that look like this: the resulting cursor has multiple rows that look like this: A1.id | A1.column1 | A1.column2 | B1.a_id_fk | B1.column1 | B1.column2 A1.id | A1.column1 | A1.column2 | B2.a_id_fk | B2.column1 | B2.column2 and so on... Is there a standard practice or method of dealing with results like this ? Clearly there is only A1, but it has many B-n relationships. I am coming close to using multiple queries instead of the "relational db way". Hopefully I am just not aware of the better way to do things. I intend to expose this query via a content provider and I would hate for all of the consumers to have to write the same aggregation logic.

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  • SQLite doesn't have booleans or date-times...but C# does

    - by DanM
    I've been thinking about using SQLite for my next project, but I'm concerned that it seems to lack proper datetime and bit data types. If I use DbLinq (or some other ORM) to generate C# classes, will the data types of the properties be "dumbed down"? Will date-time data be placed in properties of type string or double? Will boolean data be placed in properties of type int? If yes, what are the implications? I'm envisioning a scenario where I need to write a whole second layer of classes with more specific data types and do a bunch of transformations and casts, but maybe it's not so bad. If you have any experience with this or a similar scenario, what are your "lessons learned"?

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  • SQLite doesn't have booleans or date-times.

    - by DanM
    I've been thinking about using SQLite for my next project, but I'm concerned that it seems to lack proper datetime and bit data types. If I use DbLinq (or some other ORM) to generate C# classes, will the data types of the properties be "dumbed down"? Will date-time data be placed in properties of type string or double? Will boolean data be placed in properties of type int? If yes, what are the implications? I'm envisioning a scenario where I need to write a whole second layer of classes with more specific data types and do a bunch of transformations and casts, but maybe it's not as bad as I fear. If you have any experience with this or a similar scenario, how did you handle it?

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  • Using a ICollection Value in sqlite SELECT parameterized statment

    - by case23
    Im trying to get all the entrys from a sqlite Database which have the same name as the keys in a Hashtable. My Statement looks like this. // the keys from the hashtable are names equivalent // to name entrys in the SomeTable Names Collumn Hashtable names; String query = "SELECT Id, Name FROM SomeTable WHERE Name LIKE (@Names)"; SQLiteCommand command = new SQLiteCommand(query, _databaseConnection); command.Parameters.AddWithValue("@Names", names.Keys); SQLiteDataReader reader = reader.ExecuteReader(); while(reader.Read()) { Console.WriteLine("Name: {0}, ID: {1}", reader[1].ToString(), reader[0].ToString()); } Im totally sure there are similar values in the Database, but i get nothing back and the reader does not execute. Is it impossible to add a ICollection as a Parameter Value so i need to start the reader only one time?

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  • Database file is inexplicably locked during SQLite commit

    - by sweeney
    Hello, I'm performing a large number of INSERTS to a SQLite database. I'm using just one thread. I batch the writes to improve performance and have a bit of security in case of a crash. Basically I cache up a bunch of data in memory and then when I deem appropriate, I loop over all of that data and perform the INSERTS. The code for this is shown below: public void Commit() { using (SQLiteConnection conn = new SQLiteConnection(this.connString)) { conn.Open(); using (SQLiteTransaction trans = conn.BeginTransaction()) { using (SQLiteCommand command = conn.CreateCommand()) { command.CommandText = "INSERT OR IGNORE INTO [MY_TABLE] (col1, col2) VALUES (?,?)"; command.Parameters.Add(this.col1Param); command.Parameters.Add(this.col2Param); foreach (Data o in this.dataTemp) { this.col1Param.Value = o.Col1Prop; this. col2Param.Value = o.Col2Prop; command.ExecuteNonQuery(); } } this.TryHandleCommit(trans); } conn.Close(); } } I now employ the following gimmick to get the thing to eventually work: private void TryHandleCommit(SQLiteTransaction trans) { try { trans.Commit(); } catch (Exception e) { Console.WriteLine("Trying again..."); this.TryHandleCommit(trans); } } I create my DB like so: public DataBase(String path) { //build connection string SQLiteConnectionStringBuilder connString = new SQLiteConnectionStringBuilder(); connString.DataSource = path; connString.Version = 3; connString.DefaultTimeout = 5; connString.JournalMode = SQLiteJournalModeEnum.Persist; connString.UseUTF16Encoding = true; using (connection = new SQLiteConnection(connString.ToString())) { //check for existence of db FileInfo f = new FileInfo(path); if (!f.Exists) //build new blank db { SQLiteConnection.CreateFile(path); connection.Open(); using (SQLiteTransaction trans = connection.BeginTransaction()) { using (SQLiteCommand command = connection.CreateCommand()) { command.CommandText = DataBase.CREATE_MATCHES; command.ExecuteNonQuery(); command.CommandText = DataBase.CREATE_STRING_DATA; command.ExecuteNonQuery(); //TODO add logging } trans.Commit(); } connection.Close(); } } } I then export the connection string and use it to obtain new connections in different parts of the program. At seemingly random intervals, though at far too great a rate to ignore or otherwise workaround this problem, I get unhandled SQLiteException: Database file is locked. This occurs when I attempt to commit the transaction. No errors seem to occur prior to then. This does not always happen. Sometimes the whole thing runs without a hitch. No reads are being performed on these files before the commits finish. I have the very latest SQLite binary. I'm compiling for .NET 2.0. I'm using VS 2008. The db is a local file. All of this activity is encapsulated within one thread / process. Virus protection is off (though I think that was only relevant if you were connecting over a network?). As per Scotsman's post I have implemented the following changes: Journal Mode set to Persist DB files stored in C:\Docs + Settings\ApplicationData via System.Windows.Forms.Application.AppData windows call No inner exception Witnessed on two distinct machines (albeit very similar hardware and software) Have been running Process Monitor - no extraneous processes are attaching themselves to the DB files - the problem is definitely in my code... Does anyone have any idea whats going on here? I know I just dropped a whole mess of code, but I've been trying to figure this out for way too long. My thanks to anyone who makes it to the end of this question! brian UPDATES: Thanks for the suggestions so far! I've implemented many of the suggested changes. I feel that we are getting closer to the answer...however... The code above technically works however it is non-deterministic! It is not guaranteed to do anything aside from spin in neutral forever. In practice it seems to work somewhere between the 1st and 10th iteration. If i batch my commits at a reasonable interval damage will be mitigated but I really do not want to leave things in this state... More suggestions welcome!

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