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POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
 

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  1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
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    <p>I'm developing an iPhone app which is using sqlite library directly instead of CoreData. I tried to drop a table, but no matter how I tried, I always got a <code>SQLITE_LOCKED</code> instead of <code>SQLITE_DONE</code>.</p> <p>I had searched stackoverflow.com, but could not find any similar problems. Here is my code:</p> <h2><code>-DropTable:</code></h2> <pre> - (BOOL) dropTable:(NSString *)tableName{ NSString* queryBase = [NSString stringWithFormat:@"drop table if exists %@;", tableName]; const char* query = [queryBase UTF8String]; sqlite3_stmt* stmt = nil; if (sqlite3_prepare_v2([SLDBAccess sharedSLDBAccess].database, query, -1, &stmt, NULL) != SQLITE_OK){ NSAssert1(0, @"Error: failed to prepare statement with message '%s'.", sqlite3_errmsg([SLDBAccess sharedSLDBAccess].database)); } //transaction start sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "BEGIN;", NULL, NULL, NULL); /* The following line returns SQLITE_LOCKED, which the value is 6. */ int dropOperationResult = sqlite3_step(stmt); sqlite3_reset(stmt); sqlite3_finalize(stmt); BOOL operationSucceeded = NO; if(dropOperationResult == SQLITE_DONE) { operationSucceeded = YES; } //transaction end if (operationSucceeded) { sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "COMMIT;", NULL, NULL, NULL); }else { sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "ROLLBACK;", NULL, NULL, NULL); } // No means failed. return operationSucceeded; } </pre> <h2><code>-initTable:</code></h2> <pre> - (BOOL) initTimelineTableWith:(NSString *)tableName{ NSString* queryBase = [NSString stringWithFormat:@"CREATE TABLE %@ ( id INTEGER PRIMARY KEY AUTOINCREMENT, timeline_id BIGINT UNSIGNED UNIQUE, in_reply_to_screen_name TEXT, in_reply_to_status_id INTEGER UNSIGNED, in_reply_to_user_id BIGINT UNSIGNED, source TEXT, text TEXT, favorited BOOLEAN, truncated BOOLEAN, retweeted_status BIGINT UNSIGNED, retweeted BOOLEAN, user BIGINT UNSIGNED, status INTEGER UNSIGNED, create_at DATETIME, update_on DATETIME );", tableName]; const char* query = [queryBase UTF8String]; sqlite3_stmt* stmt = nil; if (sqlite3_prepare_v2([SLDBAccess sharedSLDBAccess].database, query, -1, &stmt, NULL) != SQLITE_OK){ NSAssert1(0, @"Error: failed to prepare statement with message '%s'.", sqlite3_errmsg([SLDBAccess sharedSLDBAccess].database)); } //transaction start sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "BEGIN;", NULL, NULL, NULL); int createOperationResult = sqlite3_step(stmt); sqlite3_reset(stmt); sqlite3_finalize(stmt); BOOL operationSucceeded = NO; if(createOperationResult == SQLITE_DONE) { operationSucceeded = YES; } //transaction end if (operationSucceeded) { sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "COMMIT;", NULL, NULL, NULL); SLLog(@"create table successfully!"); }else { sqlite3_exec([SLDBAccess sharedSLDBAccess].database, "ROLLBACK;", NULL, NULL, NULL); SLLog(@"create table failed!"); } // No means failed. return operationSucceeded; } </pre> <h2>Test case</h2> <pre> NSString *newTableName = @"tonny_test"; STAssertFalse([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should not exsit."); STAssertTrue([[DTModelHelper sharedDTModelHelper] initTimelineTableWith:newTableName], @"init with new table."); STAssertTrue([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should exsit after we created it."); /* The following 2 test cases always failed. */ STAssertTrue([[DTModelHelper sharedDTModelHelper] dropTable:newTableName], @"drop table operation should return OK."); STAssertFalse([[DTModelHelper sharedDTModelHelper] isTableExistWith:newTableName], @"new table should not exsit after being dropped."); </pre> <hr> <h2>Some additional explanations:</h2> <ul> <li><code>DTModeelHelper</code> is a singleton helper class which contains all the DB operations.</li> <li><code>SLDBAccess</code> is also a singleton helper class which will init the DB and establish the connection or close the connection.</li> <li><code>isTableExistWith:</code> is another method that will query the DB for whether a specified table exists or not. It works fine now.</li> </ul> <hr> <p>Does anybody have any idea about this issue?</p>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USTonny Xu
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
      1. This table or related slice is empty.
      1. VTUpMod
    1. COAre you using the database in your bundle, or did you copy it to the document directory? If it's just in your bundle the db will be read only and you cannot change anything.
      singulars
      1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
      1. USMishieMoo
    2. CO@MishieMoo Yes, I copied the database file to document folder and it works fine on insert/delete table rows.
      singulars
      1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
      1. USTonny Xu
    3. COAre there other processes that might be using the database? Or are you perhaps using a shared cache?
      singulars
      1. POtried "DROP TABLE/DROP TABLE IF EXISTS tablename", but got a SQLITE_LOCKED, instead of SQLITE_DONE
      1. USMike Sherrill 'Cat Recall'
 

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