IOS 数据库操作

参考：http://www.cnblogs.com/hanjun/archive/2012/10/29/2744573.html

总结4点：

1）open数据库

2）插入数据

3）查询数据

4）close数据库

 一、新建Empty Appliation，添加一个HomeViewController，和一个组件libsqlite3.dylib,来支持对sqlite3的连接，关闭，增删改查等操作。

1. HomeViewController.h代码：

#import <UIKit/UIKit.h>

#import "sqlite3.h"

 

@interface HomeViewController : UIViewController{

 

    sqlite3 *db; //声明一个sqlite3数据库

}

 

- (NSString *)filePath;//数据库文件的路径。一般在沙箱的Documents里边操作

 

@end

 

2. HomeViewController.m代码：

 #import "HomeViewController.h"

 

 

@interface HomeViewController ()

 

@end

 

@implementation HomeViewController

 

//该方法用于返回数据库在Documents文件夹中的全路径信息 

- (NSString *)filePath{

 

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

    NSString *documentsDir = [paths objectAtIndex:0];

    return [documentsDir stringByAppendingPathComponent:@"Contacts.sqlite"];

}

 

//打开数据库的方法 

- (void)openDB{

 

    if (sqlite3_open([[self filePath] UTF8String], &db) != SQLITE_OK) {

        sqlite3_close(db);

        NSAssert(0, @"数据库打开失败。");

    }

}

 

//插入数据方法

- (void)insertRecordIntoTableName:(NSString *)tableName

                       withField1:(NSString *)field1 field1Value:(NSString *)field1Value

                        andField2:(NSString *)field2 field2Value:(NSString *)field2Value

                        andField3:(NSString *)field3 field3Value:(NSString *)field3Value{

/*方法1：经典方法

    NSString *sql = [NSString stringWithFormat:@"INSERT INTO '%@' ('%@', '%@', '%@') VALUES('%@', '%@', '%@')", tableName, field1, field2, field3, field1Value, field2Value, field3Value];

    char *err;

    if (sqlite3_exec(db, [sql UTF8String], NULL, NULL, &err) != SQLITE_OK) {

        sqlite3_close(db);

        NSAssert(0, @"插入数据错误！");

    }

    */

   //方法2：变量的绑定方法 

    NSString *sql = [NSString stringWithFormat:@"INSERT INTO '%@' ('%@', '%@', '%@') VALUES (?, ?, ?)",tableName, field1, field2, field3];

    

    sqlite3_stmt *statement;

    

    if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &statement, nil) == SQLITE_OK) {

        sqlite3_bind_text(statement, 1, [field1Value UTF8String], -1,NULL);

        sqlite3_bind_text(statement, 2, [field2Value UTF8String], -1,NULL);

        sqlite3_bind_text(statement, 3, [field3Value UTF8String], -1,NULL);

    }

    if (sqlite3_step(statement) != SQLITE_DONE) {

        NSAssert(0, @"插入数据失败！");

        sqlite3_finalize(statement);

    }

 

                                

}

//查询数据

- (void)getAllContacts{

 

    NSString *sql = @"SELECT * FROM members";

    sqlite3_stmt *statement;

    

    if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &statement, nil) == SQLITE_OK) {

        while (sqlite3_step(statement) == SQLITE_ROW) {

            

            char *name = (char *)sqlite3_column_text(statement, 0);

            NSString *nameStr = [[NSString alloc] initWithUTF8String:name];

            

            char *email = (char *)sqlite3_column_text(statement, 1);

            NSString *emailStr = [[NSString alloc] initWithUTF8String:email];

            

            char *birthday = (char *)sqlite3_column_text(statement, 2);

            NSString *birthdayStr = [[NSString alloc] initWithUTF8String:birthday];

            

            NSString *info = [[NSString alloc] initWithFormat:@"%@ - %@ - %@",

                              nameStr, emailStr, birthdayStr];

            

            NSLog(info);

            

            [nameStr release];

            [emailStr release];

            [birthdayStr release];

            [info release];

        }

        sqlite3_finalize(statement);

    }

}

 

- (void)viewDidLoad

{

    [self openDB];

   

    [self insertRecordIntoTableName:@"members" withField1:@"name" field1Value:@"李1" andField2:@"email" field2Value:@"df@qq.com" andField3:@"birthday" field3Value:@"12-45-78"];

    

    [self insertRecordIntoTableName:@"members" withField1:@"name" field1Value:@"李2" andField2:@"email" field2Value:@"df@qq.com" andField3:@"birthday" field3Value:@"12-45-78"];

    

    [self insertRecordIntoTableName:@"members" withField1:@"name" field1Value:@"李3" andField2:@"email" field2Value:@"df@qq.com" andField3:@"birthday" field3Value:@"12-45-78"];

    

    

    

    [self getAllContacts];

    

    sqlite3_close(db);

    

    [super viewDidLoad];

}

 

@end