插入查询不起作用（FMDB）

Question

这是我用来将记录插入 sqlite 的代码 table

FMDatabase *dataBase = [self openDatabase];
    [dataBase open];
    if ([dataBase open] != YES) {
        NSLog(@"DB Error %d: %@", [dataBase lastErrorCode], [dataBase lastErrorMessage]);
    //VERY IMPORTANT
    }

    BOOL success= [dataBase executeUpdate:@"Insert into CrewUnits (pkCrewUnits,fkUnits,fkAgencyVehicles,fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, PrimaryUnit) values (?, ?, ?, ?, ?, ?);", pkCrewUnits, fkUnits, fkAgencyVehicle, fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, [NSNumber numberWithInt:1]];
    NSLog(success ?@"YES" :@"NO");
     NSLog(@"Error %d: %@", [dataBase lastErrorCode], [dataBase lastErrorMessage]);
   FMResultSet*resultSet= [dataBase executeQuery:@"select * from CrewUnits"];
    NSLog(@"ResultSet : %@", [resultSet resultDictionary]);

    [dataBase close];

数据库路径

- (FMDatabase *)openDatabase
{

    NSLog(@"Open Database");
    NSString *documents_dir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *db_path = [documents_dir stringByAppendingPathComponent:[NSString stringWithFormat:@"HPSix_05BD.db"]];    // DatabasePath
    FMDatabase *db = [FMDatabase databaseWithPath:db_path];
    if (![db open])
        NSLog(@"Failed to open database!!!!!");
    return db;
}

我正在使用相同的逻辑从 table 获取数据，这对我来说效果很好。但是我不能插入记录。我不知道我在这里做错了什么。

Answer 1

我想我明白问题所在了。您在运行之后提交 SELECT 查询。

您必须在 UPDATE 查询后立即提交。当您像现在这样选择时，UPDATE 查询尚未提交，因此不会返回。

[dataBase beginTransaction];
BOOL success= [dataBase executeUpdate:@"Insert into CrewUnits (pkCrewUnits,fkUnits,fkAgencyVehicles,fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, PrimaryUnit) values (?, ?, ?, ?, ?, ?);", pkCrewUnits, fkUnits, fkAgencyVehicle, fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, [NSNumber numberWithInt:1]];
[dataBase commit]; // commit the query
NSLog(success ?@"YES" :@"NO");
NSLog(@"Error %d: %@", [dataBase lastErrorCode], [dataBase lastErrorMessage]);
// now at this point the transaction has been committed and can be selected
FMResultSet*resultSet= [dataBase executeQuery:@"select * from CrewUnits"];
NSLog(@"ResultSet : %@", [resultSet resultDictionary]);

还有according to FMDB docs:

The parameters must start with a colon. SQLite itself supports other characters, but internally the Dictionary keys are prefixed with a colon, do not include the colon in your dictionary keys.

因此这行代码必须重写为：

BOOL success= [dataBase executeUpdate:@"Insert into CrewUnits (pkCrewUnits,fkUnits,fkAgencyVehicles,fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, PrimaryUnit) values (:pkCrewUnits,:fkUnits,:fkAgencyVehicles,:fkLookupCodes_PrimaryRole, :fkLookupCodes_LevelOfCare, :PrimaryUnit);", pkCrewUnits, fkUnits, fkAgencyVehicle, fkLookupCodes_PrimaryRole, fkLookupCodes_LevelOfCare, [NSNumber numberWithInt:1]];

最后根据您使用 next 循环结果的文档：

while ([resultSet next]) {
    //retrieve values for each record
}

Answer 2

两个问题：

您正在呼叫 open 三次。一次在 openDatabase 中，两次在调用它的代码中。

所以，如果可以的话，让你的 open 例程打开数据库，但是 return nil 如果它不能：

- (FMDatabase *)openDatabase
{
    NSLog(@"Open Database");
    NSString *documents_dir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *db_path = [documents_dir stringByAppendingPathComponent:[NSString stringWithFormat:@"HPSix_05BD.db"]];    // DatabasePath
    FMDatabase *db = [FMDatabase databaseWithPath:db_path];
    if (![db open]) {
        NSLog(@"Failed to open database!!!!!");
        return nil;
    }
    return db;
}

然后检查结果：

FMDatabase *dataBase = [self openDatabase];
if (!dataBase) {
    // quit; note, no point in checking error message as it only returns meaningful messages if you have an open database
}

调用executeQuery后，还要调用next.

FMResultSet *resultSet = [dataBase executeQuery:@"select * from CrewUnits"];
if ([resultSet next]) {
    NSLog(@"ResultSet : %@", [resultSet resultDictionary]);
} else {
    NSLog(@"No data found");
}

插入查询不起作用（FMDB）

Insert Query not working (FMDB)

ios

sqlite

fmdb