iOS Sqlite的详解

1.创建数据库

//创建数据库路径
NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@"Person.sqlite"];
NSLog(@"Path: %@", path);
//打开上面的创建的数据库，如果不存在，则会创建
//路径转为统一格式
const char *filename = [path cStringUsingEncoding:NSUTF8StringEncoding];
//#import <sqlite3.h>  以及 添加 libsqlite3.0.tbd
sqlite3 *ppDb = NULL;
int response = sqlite3_open(filename, &ppDb);
if (response == SQLITE_OK) {
NSLog(@"打开Person.sqlite数据库成功");
}else NSLog(@"打开Person.sqlite数据库失败");

2.创建表格

//创建表table,这个要熟悉数据库的建表语句，这个了解一下即可
const char *creatTable = "create table if not exists Student(name varchar, age integer, sex varchar, class integer, school varchar, address varchar, studentID varchar primary key)";
//表创建失败 table Student already exists
char *error = NULL;
response = sqlite3_exec(ppDb, creatTable, NULL, NULL, &error);
if (response == SQLITE_OK) {
NSLog(@"创建表成功");
}else{
NSLog(@"表创建失败 %s", error);
}

3.插入以及更新记录

//插入一条记录
const char *insertSql = "insert into Student values ('YaoMing', 30, 'Male', 'SofeWare 1', 'SofeWare', '广州上下九步行街', '20095531011')";
response = sqlite3_exec(ppDb, insertSql, NULL, NULL, &error);
if (response == SQLITE_OK) {
NSLog(@"插入成功");
}else{
NSLog(@"插入失败 %s", error);
}
//update 记录
const char *updateSchool = "update Student set school = '广州大学'";
response = sqlite3_exec(ppDb, updateSchool, NULL, NULL, &error);
if (response == SQLITE_OK) {
NSLog(@"update successful");
}else NSLog(@"update failed: %s", error);

4.删除行

//删除 记录
const char *delete = "delete from Student";
response = sqlite3_exec(ppDb, delete, NULL, NULL, &error);
if (response == SQLITE_OK) {
NSLog(@"delete 成功");
}else NSLog(@"删除失败 %s", error);

5.查询存储的数据

//查询所有的数据
const char *querySql = "select * from Student";
//用于存储查询出来的数据
sqlite3_stmt *ppStmt = NULL;
response = sqlite3_prepare_v2(ppDb, querySql, -1, &ppStmt, NULL);
//遍历列表中的每一条数据,拿到其中的内容
while (sqlite3_step(ppStmt) == SQLITE_ROW) {
//拿到数据中第0列的内容
const unsigned char *name = sqlite3_column_text(ppStmt, 0);
//第1列的内容
const unsigned char *age = sqlite3_column_text(ppStmt, 1);

NSLog(@"%s", name);
NSLog(@"%s", age);
//        NSString *nameStr = [NSString stringWithUTF8String:name];
//        NSLog(@"%@", nameStr);

6.drop 表

//drop table
const char *dropTable = "drop table Student";
response = sqlite3_exec(ppDb, dropTable, NULL, NULL, &error);
if (response == SQLITE_OK) {
NSLog(@"drop 成功");
}else NSLog(@"drop失败 %s", error);

7.最后一点：

sqlite3_close(ppDb);