IOS, ios9

IOS, ios9

IOS database operations: add, delete, search, and modify

First, you need to create a database: the database of this program is a trace database written in the plug-in of Firefox browser.

Steps for Firefox to find SQLite Manager:

Step 1: Find the additional component in the toolbar and click to enter

 

Step 2: Search SQP, find and download, and restart the browser after installation.

Step 3: Find SQLite Manager optimistically in the tool and click Open

SQLite Manager interface

Note: SQLite Manager is a trace-type database programming software, so only one sentence of code can be executed at a time !!!

• Create a database

-- Create table team (
-- Create a table named team
Stu_id integer primary key autoincrement,
Stu_name varchar (100 ),
Stu_password varchar (100 ),
Stu_login varchar (100)
)
-- Add information
Insert into team (stu_name, stu_password, stu_login) values ('xiaming ', '123', 'xm ')
Insert into team (stu_name, stu_password, stu_login) values ('zhangsan', '123', 'zs ')
-- Query Information
Select * from team
-- Delete information
Delete from team where stu_id = 3

 

The project directory file is as follows:

 

Here we need to import a built-in file libsqlite3.0.tbd

 

 

Procedure

 

• Implementation Project

ViewController. h

#import <UIKit/UIKit.h>#import <sqlite3.h>@interface ViewController : UIViewController@property(strong,nonatomic)UIButton *showbtn;@property(strong,nonatomic)UIButton *insertbtn;@property(strong,nonatomic)UIButton *updatebtn;@property(strong,nonatomic)UIButton *deletebtn;@end

ViewController. h

# Import "ViewController. h "# define PATH [[NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent: @" team. sqlite "] @ interface ViewController () @ end @ implementation ViewController-(void) viewDidLoad {[super viewDidLoad]; // obtain the NSLog (@" % @", [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) la StObject]); [self button];}-(void) button {self. showbtn = [UIButton buttonWithType: UIButtonTypeSystem]; self. showbtn. frame = CGRectMake (100, 50,200, 50); [self. showbtn setTitle: @ "database display" forState: UIControlStateNormal]; [self. showbtn addTarget: self action: @ selector (showSql) forControlEvents: UIControlEventTouchUpInside]; [self. view addSubview: self. showbtn]; self. insertbtn = [UIButton buttonWithType: UIButt OnTypeSystem]; self. insertbtn. frame = CGRectMake (100,100,200, 50); [self. insertbtn setTitle: @ "add Database" forState: UIControlStateNormal]; [self. insertbtn addTarget: self action: @ selector (insertSql) forControlEvents: UIControlEventTouchUpInside]; [self. view addSubview: self. insertbtn]; self. updatebtn = [UIButton buttonWithType: UIButtonTypeSystem]; self. updatebtn. frame = CGRectMake (100,150,200, 50); [self. upd Atebtn setTitle: @ "database modification" forState: UIControlStateNormal]; [self. updatebtn addTarget: self action: @ selector (updateSql) forControlEvents: UIControlEventTouchUpInside]; [self. view addSubview: self. updatebtn]; self. deletebtn = [UIButton buttonWithType: UIButtonTypeSystem]; self. deletebtn. frame = CGRectMake (100,200,200, 50); [self. deletebtn setTitle: @ "delete database" forState: UIControlStateNormal]; [self. deletebtn add Target: self action: @ selector (deleteSql) forControlEvents: UIControlEventTouchUpInside]; [self. view addSubview: self. deletebtn] ;}# pragma mark-show all information in the data table-(void) showSql {NSLog (@ "show database information"); // database sqlite3 * db; // open the database int result = sqlite3_open ([PATH UTF8String], & db) according to the specified database file storage PATH; // create the execution command object sqlite3_stmt * stmt; // if the database is successfully opened (result = SQLITE_ OK) {NSLog (@ "connection successful"); // execute the preprocessing command int res = sqlite3_prepare_v2 (Db, "select * from team",-1, & stmt, nil); if (res = SQLITE_ OK) {// cyclically traverse the row information of the data table while (sqlite3_step (stmt) = SQLITE_ROW) {// obtain the information of the integer column in the data table int stu_id = sqlite3_column_int (stmt, 0 ); NSLog (@ "stu_id is % d", stu_id); // obtain the NSLog (@ "% @", [NSString stringWithFormat: @ "% s", sqlite3_column_text (stmt, 1)]); NSLog (@ "% @", [NSString stringWithFormat: @ "% s", sqlite3_column_text (stmt, 2)]); NSLog (@ "% @", [NSStri Ng stringWithFormat: @ "% s", sqlite3_column_text (stmt, 3)]) ;}}# pragma mark-add information-(void) insertSql {sqlite3 * db; sqlite3_stmt * stmt; sqlite3_open ([PATH UTF8String], & db); int rst = sqlite3_prepare_v2 (db, "insert into team (stu_name, stu_password, stu_login) values (?,?,?) ",-1, & stmt, nil); sqlite3_bind_text (stmt, 1," wangwu ",-1, nil); sqlite3_bind_text (stmt, 2," 123456 ",-1, nil); sqlite3_bind_text (stmt, 3, "ww",-1, nil); // determine whether the value is added successfully if (rst = SQLITE_ OK) {if (SQLITE_DONE = sqlite3_step (stmt) {NSLog (@ "add OK");} else {NSLog (@ "add fail ");}}} # pragma mark-modify Database-(void) updateSql {sqlite3 * db; sqlite3_stmt * stmt; sqlite3_open ([PATH UTF8String], & db); // method 1/* int Res = sqlite3_prepare_v2 (db, "update team set stu_name = (?), Stu_password = (?), Stu_login = (?) Where stu_id = 2 ",-1, & stmt, nil); sqlite3_bind_text (stmt, 1," xiaoming ",-1, nil); sqlite3_bind_text (stmt, 2, "123456",-1, nil); sqlite3_bind_text (stmt, 3, "xm",-1, nil); * // method 2 int rst = sqlite3_prepare_v2 (db, "update team setstu_name = 'zl', stu_password = 'zl123 ', stu_login = 'zhangsan' where stu_id = 4",-1, & stmt, nil ); // determine whether the modification is successful if (rst = SQLITE_ OK) {if (SQLITE_DONE = sqlite3_step (stmt) {NSLog (@ "update OK ");} else {NSLog (@ "update fail") ;}}- (void) deleteSql {sqlite3 * db; sqlite3_stmt * stmt; sqlite3_open ([PATH UTF8String], & db ); int rst = sqlite3_prepare_v2 (db, "delete from team where stu_id = 9",-1, & stmt, nil); // determine whether the deletion is successful if (rst = SQLITE_ OK) {if (SQLITE_DONE = sqlite3_step (stmt) {NSLog (@ "delete OK");} else {NSLog (@ "delete fail ");}}}
-(Void) didReceiveMemoryWarning {[super didreceivemorywarning]; // Dispose of any resources that can be recreated.} @ end