FMDB操作数据库

#define KDataBasePath @“...”FMDatabase *db = [FMDatabase databaseWithPath:KDataBasePath];```1、打开数据库[db open]2、creat insert 用同一方法：将SQL语句转化为NSString [db executeUpdate:SQLCommandString]；3、select 查询用query 返回值：FMResultSet类型 是个集合FMResultSet *result = [db executeQuery:SQLCommandString]；if ([result next]) {   NSLog(@"select success");   //拿出查询的字段数据   [result stringForColumn:@"name"];}4、关闭数据库[db close];

例子：

打开数据库#define KDataBasePath @“...”FMDatabase *db = [FMDatabase databaseWithPath:KDataBasePath];    if (![db open]) {        NSLog(@"could not open db");        return;    }else {        NSLog(@"open db");    }```

创建数据表 -(void)creatTableWithTableName{    NSString *creatString = [NSString stringWithFormat:@"CREATE TABLE IF NOT EXISTS 'user' ('id' INTEGER PRIMARY KEY AUTOINCREMENT, 'name' TEXT,  'password' TEXT)"];    BOOL result = [db executeUpdate:creatString];    if (result) {        NSLog(@"tabel success");    }else {        NSLog(@"tabel fail");    }}

查询数据表是否存在-(void)queryTable:(NSString *)tableName{    if ([db executeQuery:@"select count(*) as 'count' from sqlite_master where type = 'table' and name = %@",tableName]) {        NSLog(@"tabel 已存在");    }else {        NSLog(@"tabel 不存在");    }}

插入一条数据-(BOOL)insertDataWithId:(NSInteger)user_id                   Name:(NSString *)name               Password:(NSString *)password{    //有问题------   BOOL result = [db executeUpdate:@"insert into user (name,password) values (?,?)",name,password];    if (result) {        NSLog(@"insert success");    }else {        NSLog(@"insert fail");    }    return result;}

select选择数据-(BOOL)selectTableWithUserName:(NSString *)name Password:(NSString *)password{    BOOL resultSelect = NO;    NSString *selectString = [NSString stringWithFormat:@"select *from 'user' where name = '%@' and password = '%@'",name,password];    FMResultSet *result = [db executeQuery:selectString];    if ([result next]) {        resultSelect = YES;        NSLog(@"select success");        NSLog(@"%@",[result stringForColumn:@"name"]);    }else{        NSLog(@"select fail");    }    return resultSelect;}

关闭数据库-(void)closeDataBase{    if (![db close]) {        NSLog(@"数据库关闭异常，请检查");        return;    }else {        NSLog(@"关闭成功");    }}