iOS_FMDB使用

1/3. 向项目中引入FMDB库，可以使用cocoapods也可以直接手动添加，手动添加时需要自己导入对libsqlite3.tbd的依赖。

2/3. 在Main.stroryboard里在vc中添加几个按钮并对按钮的点击事件进行方法关联

关联按钮点击事件

3/3. 代码都在ViewController.m中，代码很简单，如下。
这里没有涉及多线程的东西，因为数据库使用情况不多，就算用了也很少用多到多线程，等以后用到了我再更新。

//
//  ViewController.m
//  fmdbTest
//
//  Created by yuweiMac on 16/4/29.
//  Copyright © 2016年 yuweiMac. All rights reserved.
//

#import "ViewController.h"

#import "FMDB.h"

@interface ViewController ()

@property (nonatomic, strong) FMDatabase *fmDB;

@end

#define TABLENAME @"info"
#define ID @"id"
#define NAME @"name"
#define AGE @"age"
#define ADDRESS @"address"

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSString *docPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
    self.fmDB = [FMDatabase databaseWithPath:[docPath stringByAppendingPathComponent:@"fmtest.db"]];
    
    NSLog(@"%@",docPath);
}


- (IBAction)createInfoTable:(UIButton *)sender {
    
    if ([self.fmDB open]) {
        
        if (![self.fmDB tableExists:TABLENAME]) {
            NSString *sqlCreateTable =  [NSString stringWithFormat:@"CREATE TABLE IF NOT EXISTS '%@' ('%@' INTEGER PRIMARY KEY AUTOINCREMENT, '%@' TEXT, '%@' INTEGER, '%@' TEXT)",TABLENAME,ID,NAME,AGE,ADDRESS];
            NSLog(@"%@",sqlCreateTable);
            BOOL res = [self.fmDB executeUpdate:sqlCreateTable];
            
            if (!res) {
                NSLog(@"error when creating info table");
            } else {
                NSLog(@"success to creating info table");
            }
        }

        sender.enabled = NO;
        
        [self.fmDB close];
    }

}


- (IBAction)addData2Info:(UIButton *)sender {
    
    if ([self.fmDB open]) {
        NSString *insertSql1= [NSString stringWithFormat:
                               @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES ('%@', '%@', '%@')",
                               TABLENAME, NAME, AGE, ADDRESS, @"张三", @"13", @"济南"];
        NSLog(@"%@",insertSql1);
        BOOL res = [self.fmDB executeUpdate:insertSql1];
        
        NSString *insertSql2 = [NSString stringWithFormat:
                                @"INSERT INTO '%@' ('%@', '%@', '%@') VALUES ('%@', '%@', '%@')",
                                TABLENAME, NAME, AGE, ADDRESS, @"李四", @"12", @"济南"];
        NSLog(@"%@",insertSql2);
        BOOL res2 = [self.fmDB executeUpdate:insertSql2];
        
        if (!( res && res2 )) {
            NSLog(@"error when insert info table");
        } else {
            NSLog(@"success to insert info table");
        }
        
        [self.fmDB close];
        
    }
    
}


- (IBAction)changeData2Info:(UIButton *)sender {
    
    if ([self.fmDB open]) {
        NSString *updateSql = [NSString stringWithFormat:
                               @"UPDATE '%@' SET %@ = '%@' WHERE %@ = '%@'",
                               TABLENAME,   AGE,  @"15" ,AGE,  @"13"];
        NSLog(@"%@",updateSql);
        BOOL res = [self.fmDB executeUpdate:updateSql];
        
        if (!res) {
            NSLog(@"error when update info table");
        } else {
            NSLog(@"success to update info table");
        }
        
        [self.fmDB close];
        
    }

}


- (IBAction)deleteData2Info:(UIButton *)sender {
    
    if ([self.fmDB open]) {
        
        NSString *deleteSql = [NSString stringWithFormat:
                               @"delete from %@ where %@ = '%@'",
                               TABLENAME, NAME, @"张三"];
        NSLog(@"%@",deleteSql);
        BOOL res = [self.fmDB executeUpdate:deleteSql];
        
        if (!res) {
            NSLog(@"error when delete info table");
        } else {
            NSLog(@"success to delete info table");
        }
        [self.fmDB close];
        
    }

    
}


- (IBAction)queryDataOfInfo:(UIButton *)sender {
    
    if ([self.fmDB open]) {
        NSString * sql = [NSString stringWithFormat:
                          @"SELECT * FROM %@ ",TABLENAME];
        NSLog(@"%@",sql);
        FMResultSet * rs = [self.fmDB executeQuery:sql];
        while ([rs next]) {
            int Id = [rs intForColumn:ID];
            NSString * name = [rs stringForColumn:NAME];
            NSString * age = [rs stringForColumn:AGE];
            NSString * address = [rs stringForColumn:ADDRESS];
            NSLog(@"id = %d, name = %@, age = %@  address = %@", Id, name, age, address);
            /*
             FMResultSet 还有以下方法来解析数据到指定形式:
             
             intForColumn:
             longForColumn:
             longLongIntForColumn:
             boolForColumn:
             doubleForColumn:
             stringForColumn:
             dateForColumn:
             dataForColumn:
             dataNoCopyForColumn:
             UTF8StringForColumnName:
             objectForColumnName:
             
             */
        }
        
        [self.fmDB close];
    }
}


@end