对fmdb简单的封装

一直想对FMDB 进行封装一下，却不知道怎么去封装，今天闲来没事，就简单封装了一下，如果有什么不对的地方请大家指出

首先自己定义了一个单例MySqlTool,在其.h文件中实现

#import <Foundation/Foundation.h>

#import "FMDatabase.h"

@interface MySqlTool : NSObject

@property (nonatomic,strong)FMDatabase *db;

+ (MySqlTool *)sharedInstance;

- (void)creatTable:(NSString*)tableName; //创建表

- (void)insertData:(NSDictionary*)dic intoTable:(NSString *)tableName; //插入数据

- (void)deleteData:(NSDictionary *)dic fromTable:(NSString *)tableName; //删除单个数据

- (NSDictionary *)queryDataFromTable:(NSString *)tableName;//获取表tableName中所有的数据

@end

并在.m文件中实现一下方法

#import "MySqlTool.h"

#import "FMDatabaseAdditions.h"

static MySqlTool *mySqlTool = nil;

@implementation MySqlTool

@synthesize db = db;

+ (MySqlTool *)sharedInstance

{

    static dispatch_once_t onceDispatch;

    dispatch_once(&onceDispatch,^{

        

        mySqlTool = [[MySqlTool alloc]init];

    });

    return mySqlTool;

}

//获得存放数据库文件的沙盒地址

- (NSString *)databaseFilePath

{

    NSArray *filePath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentPath = [filePath objectAtIndex:0];

    NSLog(@"%@",filePath);

    NSString *dbFilePath = [documentPath stringByAppendingPathComponent:@"db.sqlite"];

    return dbFilePath;

    

}

//创建数据库的操作

- (void)creatDatabase

{

    db = [[FMDatabase databaseWithPath:[self databaseFilePath]]retain];

    

}

- (void)creatTable:(NSString*)tableName

{

    //先判断数据库是否存在，如果不存在，创建数据库

    if (!db) {

        [self creatDatabase];

    }

    //判断数据库是否已经打开，如果没有打开，提示失败

    if (![db open]) {

        NSLog(@"数据库打开失败");

        return;

    }

    //为数据库设置缓存，提高查询效率

    [db setShouldCacheStatements:YES];

    

    //判断数据库中是否已经存在这个表，如果不存在则创建该表

    if ([db open]) {

        if (![db tableExists:tableName]) {

            NSString *sql = [NSString stringWithFormat:@"CREATE TABLE '%@' ('name' CHAR(30) PRIMARY KEY, 'age' INTEGER)",tableName];

            BOOL res = [db executeUpdate:sql];

            if (!res) {

                debugLog(@"error when creating db table");

            } else {

                debugLog(@"succ to creating db table");

            }

            [db close];

        }else{

            debugLog(@"table exist!!!!!");

        }

    } else {

        debugLog(@"error when open db");

    }

}

- (void)insertData:(NSDictionary*)dic intoTable:(NSString *)tableName

{

    //判断是否有数据库

    if (!db) {

        [self creatDatabase];

    }

    if (![db open]) {

        NSLog(@"db open error");

        return;

    }

    //判断数据库中是否已经存在这个表，如果不存在则创建该表

    if (![db tableExists:tableName]) {

        [self creatTable:tableName];

    }

    // 查询表中是否有该条数据，有则修改，无则插入

    NSString *seachStr = [NSString stringWithFormat:@"select * from %@ where name = ?",tableName];

    FMResultSet *rs = [db executeQuery:seachStr,[dic objectForKey:@"name"]];

    if ([rs next]) {

        NSString *updateStr = [NSString stringWithFormat:@"update %@ set age = ? where name = ?",tableName];

        BOOL res = [db executeUpdate:updateStr,[dic objectForKey:@"age"],[dic objectForKey:@"name"]];

        if (res) {

            NSLog(@"data update success!");

        }else{

            NSLog(@"data update fail!");

        }

    }else{

        NSString *insertStr = [NSString stringWithFormat:@"INSERT INTO %@ (name, age) VALUES (?,?)",tableName];

        BOOL res = [db executeUpdate:insertStr,[dic objectForKey:@"name"],[dic objectForKey:@"age"]];

        if (res) {

            NSLog(@"data insert success!");

        }else{

            NSLog(@"data insert fail!");

        }

        

    }

    [db close];

    

}

- (void)deleteData:(NSDictionary *)dic fromTable:(NSString *)tableName

{

    //判断是否有数据库

    if (!db) {

        [self creatDatabase];

    }

    if (![db open]) {

        NSLog(@"db open error");

        return;

    }

    //判断数据库中是否已经存在这个表，如果不存在则创建该表

    if (![db tableExists:tableName]) {

        [self creatTable:tableName];

    }

    //判断数据库中是否有这条数据，有则删除

    NSString *sqlStr = [NSString stringWithFormat:@"select * from %@ where name = ?",tableName];

    FMResultSet *rs = [ db executeQuery:sqlStr,[dic objectForKey:@"name"]];

    if ([rs next]) {

          NSString *deleteStr = [NSString stringWithFormat:@"delete from %@ where name = ?",tableName];

        BOOL res = [db executeUpdate:deleteStr,[dic objectForKey:@"name"]];

        if (res ) {

            NSLog(@"delete data sucess!!!!");

        }else{

            NSLog(@"delete data failure!");

        }

    }

    [db close];

}

- (NSDictionary *)queryDataFromTable:(NSString *)tableName

{

    //判断是否有数据库

    if (!db) {

        [self creatDatabase];

    }

    if (![db open]) {

        NSLog(@"db open error");

        return nil;

    }

    //判断数据库中是否已经存在这个表，如果不存在则创建该表

    if (![db tableExists:tableName]) {

        [self creatTable:tableName];

    }

    if ([db open]) {

        NSString * sql = [NSString stringWithFormat:@"select * from %@",tableName];

        FMResultSet * rs = [db executeQuery:sql];

        while ([rs next]) {

            NSString * name = [rs stringForColumn:@"name"];

            int  age = [rs intForColumn:@"age"];

            NSLog(@"name = %@,age = %d",name,age);

            NSDictionary *divc = [[NSDictionary alloc]initWithObjectsAndKeys:name,@"name",[NSNumber numberWithInt:age],@"age", nil];

            return divc;

        }

        [db close];

    }

}

@end