Added method to validate a SQL statement

src/FMDatabaseAdditions.h

@@ -28,4 +28,6 @@
 - (FMResultSet*)getTableSchema:(NSString*)tableName;
 - (BOOL)columnExists:(NSString*)tableName columnName:(NSString*)columnName;
 
+- (BOOL)validateSQL:(NSString*)sql error:(NSError**)error;
+
 @end

src/FMDatabaseAdditions.m

@@ -111,4 +111,38 @@ - (BOOL)columnExists:(NSString*)tableName columnName:(NSString*)columnName {
     return returnBool;
 }
 
+- (BOOL)validateSQL:(NSString*)sql error:(NSError**)error {
+	sqlite3_stmt *pStmt = NULL;
+	BOOL validationSucceeded = YES;
+	BOOL keepTrying = YES;
+    int numberOfRetries = 0;
+	
+    [self setInUse:YES];
+	while (keepTrying == YES) {
+		keepTrying = NO;
+		int rc = sqlite3_prepare_v2(db, [sql UTF8String], -1, &pStmt, 0);
+		if (rc == SQLITE_BUSY || rc == SQLITE_LOCKED) {
+			keepTrying = YES;
+			usleep(20);
+			
+			if (busyRetryTimeout && (numberOfRetries++ > busyRetryTimeout)) {
+				NSLog(@"%s:%d Database busy (%@)", __FUNCTION__, __LINE__, [self databasePath]);
+				NSLog(@"Database busy");
+			}			
+		} else if (rc != SQLITE_OK) {
+			validationSucceeded = NO;
+			if (error) {
+				*error = [NSError errorWithDomain:NSCocoaErrorDomain 
+											 code:[self lastErrorCode]
+										 userInfo:[NSDictionary dictionaryWithObject:[self lastErrorMessage] 
+																			  forKey:NSLocalizedDescriptionKey]];
+			}
+		}
+	}
+	[self setInUse:NO];
+	sqlite3_finalize(pStmt);
+	
+	return validationSucceeded;
+}
+
 @end