FMDB基本操作
1.實例化FMDatabase
//paths: ios下Document路徑,Document為ios中可讀寫的文件夾
NSArray *paths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
//dbPath: 數據庫路徑,在Document中。
NSString *dbPath = [documentDirectorystringByAppendingPathComponent:@"Test.db"];
//創建數據庫實例 db?這里說明下:如果路徑中不存在"Test.db"的文件,sqlite會自動創建"Test.db"
FMDatabase *db= [FMDatabase databaseWithPath:dbPath] ;
if (![db open]) {
NSLog(@"Could not open db.");
return ;
}
2.創建表
//創建一個名為User的表,有兩個字段分別為string類型的Name,integer類型的Age
[db executeUpdate:@"CREATE TABLE User (Name text,Ageinteger)"];
3.插入
//插入數據使用OC中的類型 text對應為NSString integer對應為NSNumber的整形
[db executeUpdate:@"INSERT INTO User (Name,Age) VALUES(?,?)",@"張三",[NSNumber numberWithInt:20]];
4.更新
//更新數據 將“張三”更改為“李四”
[db executeUpdate:@"UPDATE User SET Name = ? WHERE Name = ?",@"李四",@"張三"];
5.刪除
//刪除數據
[db executeUpdate:@"DELETE FROM User WHERE Name = ?",@"張三"];
6.查詢
//返回數據庫中第一條滿足條件的結果
NSString *aa=[db stringForQuery:@"SELECT Name FROM User WHERE Age =?",@"20"];
//返回全部查詢結果
FMResultSet *rs=[db executeQuery:@"SELECT * FROM User"];
rs=[db executeQuery:@"SELECT * FROM User WHERE Age =?",@"20"];
while ([rs next]){
NSLog(@"%@ %@",[rs stringForColumn:@"Name"],[rsstringForColumn:@"Age"]);
}
[rs close];
總結
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