在尝试从阵列中删除对象时已经解除分配Erro的过度释放

时间:2015-10-30 06:23:02

标签: ios objective-c

-(void)runQuery:(const char *)query isQueryExecutable:(BOOL)queryExecutable{
    // Create a sqlite object.
    sqlite3 *sqlite3Database;

    // Set the database file path.
    NSString *databasePath = [self.documentsDirectory stringByAppendingPathComponent:self.databaseFilename];

    // Initialize the results array.
    if (self.arrResults != nil) {
        //if(self.arrResults.count>0)
            [self.arrResults removeAllObjects];
        self.arrResults = nil;
    }
    self.arrResults = [[NSMutableArray alloc] init];

    // Initialize the column names array.
    if (self.arrColumnNames != nil) {
        [self.arrColumnNames removeAllObjects];
        self.arrColumnNames = nil;
    }
    self.arrColumnNames = [[NSMutableArray alloc] init];


    // Open the database.
    BOOL openDatabaseResult = sqlite3_open([databasePath UTF8String], &sqlite3Database);
    if(openDatabaseResult == SQLITE_OK) {
        // Declare a sqlite3_stmt object in which will be stored the query after having been compiled into a SQLite statement.
        sqlite3_stmt *compiledStatement;

        // Load all data from database to memory.
        BOOL prepareStatementResult = sqlite3_prepare_v2(sqlite3Database, query, -1, &compiledStatement, NULL);
        if(prepareStatementResult == SQLITE_OK) {
            // Check if the query is non-executable.
            if (!queryExecutable){
                // In this case data must be loaded from the database.

                // Declare an array to keep the data for each fetched row.
                NSMutableArray *arrDataRow;

                // Loop through the results and add them to the results array row by row.
                while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
                    // Initialize the mutable array that will contain the data of a fetched row.
                    arrDataRow = [[NSMutableArray alloc] init];

                    // Get the total number of columns.
                    int totalColumns = sqlite3_column_count(compiledStatement);

                    // Go through all columns and fetch each column data.
                    for (int i=0; i<totalColumns; i++){
                        // Convert the column data to text (characters).
                        char *dbDataAsChars = (char *)sqlite3_column_text(compiledStatement, i);

                        // If there are contents in the currenct column (field) then add them to the current row array.
                        if (dbDataAsChars != NULL) {
                            // Convert the characters to string.
                            [arrDataRow addObject:[NSString  stringWithUTF8String:dbDataAsChars]];
                        }else{
                            //added by keerti
                            [arrDataRow addObject:@""];
                        }

                        // Keep the current column name.
                        if (self.arrColumnNames.count != totalColumns) {
                            dbDataAsChars = (char *)sqlite3_column_name(compiledStatement, i);
                            [self.arrColumnNames addObject:[NSString stringWithUTF8String:dbDataAsChars]];
                        }
                    }

                    // Store each fetched data row in the results array, but first check if there is actually data.
                    if (arrDataRow.count > 0) {
                        [self.arrResults addObject:arrDataRow];
                    }
                }
            }
            else {
                // This is the case of an executable query (insert, update, ...).

                // Execute the query.
                bool done = sqlite3_step(compiledStatement) == SQLITE_DONE;
                if (done) {
                    // Keep the affected rows.
                    self.affectedRows = sqlite3_changes(sqlite3Database);

                    // Keep the last inserted row ID.
                    self.lastInsertedRowID = sqlite3_last_insert_rowid(sqlite3Database);
                }
                else {
                    // If could not execute the query show the error message on the debugger.
                    NSLog(@"DB Error: %s", sqlite3_errmsg(sqlite3Database));
                }
            }
        }
        else {
            // In the database cannot be opened then show the error message on the debugger.
            NSLog(@"%s", sqlite3_errmsg(sqlite3Database));
        }

        // Release the compiled statement from memory.
        sqlite3_finalize(compiledStatement);

    }

    // Close the database.
    sqlite3_close(sqlite3Database);
}

上面是执行传递给它的查询的函数。我从多个班级调用它,但有时候我调用[self.arrResults removeAllObjects]会导致应用程序崩溃。任何人都可以指导如何处理方案。任何帮助将不胜感激。

0 个答案:

没有答案