Question

我正在开发应用程序，我将数据存储在数据库中，

在将数据存储到DB时，我无法更新DB中的列值，

这是我的代码：

我将更新查询传递给此方法：

QUERY = UPDATE Tbl SET favStatus ='0' WHERE Merchant_ID='1522' and Voucher_Id='5038'

//调用方法..

[self UpdateStatus：QUERY];

-(void)UpdateStatus:(NSString*)Query{

    // Get the documents directory
    databasePath=[self GetDBPath];

    if(sqlite3_open([databasePath UTF8String],&contactDB)==SQLITE_OK)
    {
        sqlite3_stmt *compiledStmt;

        if(sqlite3_prepare_v2(contactDB, [Query UTF8String],-1,&compiledStmt, NULL)==SQLITE_OK)
        {
            NSLog(@"Successful update");
        }
        sqlite3_step(compiledStmt);
        sqlite3_close(contactDB);
    }
}

我的Tbl包含Col1，Col2，Col3，Col4，favStatus，Col6 6列，我想更新内部值favStatus列。

写完此内容后，即使日志显示favStatus

，Successful update列值也不会更新

我的错误在哪里？请帮忙。

感谢advnace。

Answer 1

您能否检查一下名为favStatus的col是bool类型或数据库中定义的字符串类型。如果在db上输入字符串值，但列fvStatus为bool类型。并输入VoucherId和商家ID值作为字符串。请检查DB中的值是否为字符串。

你能分享你的Tb1 Schema结构。

更新：

//
//  VMViewController.m
//  iDev_Sqlite
//
//  Created by Pathik on 3/14/14.
//  Copyright (c) 2014 Pathik. All rights reserved.
//

#import "VMViewController.h"
#import <sqlite3.h>

@interface VMViewController ()
{
    sqlite3     *sqliteObj;
    NSString    *databasePath;
}
@end

@implementation VMViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self createDatabase];
   [self insertValuesInTable];

    [self updateValuesInTable];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - SQLITE Actions

-(void)createDatabase{

    NSString *docsDir;
    NSArray *dirPaths;

    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    docsDir = [dirPaths objectAtIndex:0];

    // Build the path to the database file
    databasePath = [[NSString alloc] initWithString: [docsDir stringByAppendingPathComponent: @"VM_TEST_DB.sqlite"]];

    NSFileManager *filemgr = [NSFileManager defaultManager];

    if ([filemgr fileExistsAtPath: databasePath ] == NO)
    {
        const char *dbpath = [databasePath UTF8String];

        if (sqlite3_open(dbpath, &sqliteObj) == SQLITE_OK)
        {
            char *errMsg;
            const char *sql_stmt = "CREATE TABLE IF NOT EXISTS tbl1 (ID INTEGER PRIMARY KEY AUTOINCREMENT, favStatus INTEGER, Voucher_ID TEXT, Merchent_ID TEXT)";

            if (sqlite3_exec(sqliteObj, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
            {
                NSLog(@"Failed to create table");
            }

            sqlite3_close(sqliteObj);

        } else {
            NSLog(@"Failed to open/create database");
        }
    }
}




-(void)insertValuesInTable{
    sqlite3_stmt    *statement;
    const char *dbpath = [databasePath UTF8String];

    if (sqlite3_open(dbpath, &sqliteObj) == SQLITE_OK) {
        NSString *insertSQL = [NSString stringWithFormat:
                               @"INSERT INTO tbl1 (favStatus,Voucher_ID,Merchent_ID) VALUES (0,'102','102')"];

        const char*insert_stmt = [insertSQL UTF8String];
        sqlite3_prepare_v2(sqliteObj, insert_stmt,  -1, &statement, NULL);
        if (sqlite3_step(statement) == SQLITE_DONE) {
            NSLog(@"Insert Successfully||");
        } else {
            NSLog(@"INSERT OPERTAION FALIED||");
        }


        sqlite3_finalize(statement);
        sqlite3_close(sqliteObj);
    }
}

-(void)updateValuesInTable{

    if(sqlite3_open([databasePath UTF8String], &sqliteObj) == SQLITE_OK) {

        NSString *cmd = [NSString stringWithFormat:@"UPDATE tbl1 SET favStatus=1 WHERE Voucher_ID='101' AND Merchent_ID='101';"];
        const char * sql = [cmd UTF8String];
        sqlite3_stmt *compiledStatement;
        if(sqlite3_prepare_v2(sqliteObj, sql, -1, &compiledStatement, NULL) == SQLITE_OK) {
            sqlite3_step(compiledStatement); // Here is the added step.
            NSLog(@"update SUCCESS - executed command %@",cmd);
        }
        else {
            NSLog(@"update FAILED - failed to execute command %@",cmd);
        }

        sqlite3_finalize(compiledStatement);

    }
    else {
        NSLog(@" FAILED - failed to open database");
    }

    sqlite3_close(sqliteObj);


}


![output][1]
@end


  [1]: http://i.stack.imgur.com/q0RTU.png

Answer 2

请检查名为favStatus的列是bool类型或数据库中定义的字符串类型。

sqlite3_prepare_v2(_contactDB, insert_stmt,-1, &statement, NULL);

if (sqlite3_step(statement) == SQLITE_DONE)
{
           ///successful 
} 
else 
{
          ///Unsuccessful 
}

在您的代码中尝试此操作...

无法更新sqlite中的列

2 个答案: