sqlite--代码操作
1.创建数据库
NSString * docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];
NSLog(@"%@",docPath);
NSString * filePath = [docPath stringByAppendingPathComponent:@"stu.sql"];
if (sqlite3_open([filePath UTF8String], &_mySQL)!=SQLITE_OK) {
NSLog(@"open error");
return 0;
}
NSLog(@"open ok");
2.创建表
NSString *createTablesql = @"create TABLE IF NOT EXISTS Student (id integer primary key autoincrement,name varchar(20),address varchar(20),icon blob)";
char *error = nil;
if (sqlite3_exec(_mySQL, [createTablesql UTF8String], nil, nil, &error)!=SQLITE_OK) {
NSLog(@"creat table error");
return 0;
}
NSLog(@"creat table ok");
3.插入数据
NSString *insertSql = @"insert into Student (name,address,icon) values (?,?,?)";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(mysql, [insertSql UTF8String], -1, &statement, NULL) != SQLITE_OK) {
NSLog(@"insert prepare error");
return;
}else{
NSLog(@"insert prepare ok");
NSData * imageData = UIImagePNGRepresentation(self.iconImageView.image);
sqlite3_bind_text(statement, 1, [_nameTextField.text UTF8String], -1, NULL);
sqlite3_bind_text(statement, 2, [_addTextField.text UTF8String], -1, NULL);
sqlite3_bind_blob(statement, 3, [imageData bytes], (int)[imageData length], NULL);
if(sqlite3_step(statement)!=SQLITE_DONE){
NSLog(@"insert error");
}else{
NSLog(@"insert ok");
}
}
sqlite3_finalize(statement);
4.查询数据
NSString *selectSql = @"select * from Student";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(mysql, [selectSql UTF8String], -1, &statement, NULL) != SQLITE_OK) {
NSLog(@"read prepare error");
return;
}else{
NSLog(@"read prepare ok");
while (sqlite3_step(statement)==SQLITE_ROW) {
Student * stu = [[Student alloc]init];
char * name = (char *)sqlite3_column_text(statement, 1);
char * address = (char *)sqlite3_column_text(statement, 2);
Byte * bytes = (Byte *)sqlite3_column_blob(statement, 3);
int length = sqlite3_column_bytes(statement, 3);
NSData * data = [NSData dataWithBytes:bytes length:length];
UIImage * image = [UIImage imageWithData:data];
stu.name = [NSString stringWithUTF8String:name];
stu.address = [NSString stringWithUTF8String:address];
stu.icon = image;
[_studentArray addObject:stu];
}
}
