sqlite3基本用法
在ios上使用sqlite3实现创建数据库，插入或更新数据记录，删除记录，查询记录功能。
创建数据表：
create table sudent {
integer id primary key,
text name,
text age,
}
首先要引入 libsqlite3.dylib
//////.h文件
#import <Foundation/Foundation.h>
#import "sqlite3.h"
@interface myDBRecord : NSObject
+(NSString *)dataFilePath;
+(BOOL)openDataBase;
+(void)createTable;
+(void)insertRecord:(NSString *)name Age:(NSString *)age ;
+(void)deleteAllRecord ;
+(NSMutableArray *)selectRecordWidthSQL:(NSString *)sql;
@end
/////.m文件
#import "myDBRecord.h"
@implementation myDBRecord
static sqlite3 *database;
//数据库目录
+(NSString *)dataFilePath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask,YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
return [documentsDirectory stringByAppendingPathComponent:@"MyDB.db"];
}
//打开数据库
+(BOOL)openDataBase{
if (sqlite3_open([[myDBRecord dataFilePath] UTF8String], &database)!=SQLITE_OK) {
sqlite3_close(database);
NSLog(@"打开数据表失败。");
returnNO;
}
return YES;
}
// 创建student数据表
+(void)createTable{
if ([self openDataBase]) {
char *errorMsg;
char *studentTable ="create table if not exists student (id integer primary key , my_name text,my_age text);";
if (sqlite3_exec (database, studentTable,NULL,NULL, &errorMsg) != SQLITE_OK) {
sqlite3_close(database);
NSLog(@"创建数据表失败。%@",errorMsg);
}
}
sqlite3_close(database);
}
// 插入记录数
+(void)insertRecord:(NSString *)name Age:(NSString *)age {
char *errorMsg = NULL;
//
char *insertSql ="INSERT OR REPLACE INTO student (my_name, my_age) VALUES (?, ?)";
sqlite3_stmt *stmt;
if (sqlite3_prepare_v2(database, insertSql, -1, &stmt,nil) == SQLITE_OK) {
sqlite3_bind_text(stmt, 1, [name UTF8String], -1,NULL);
sqlite3_bind_text(stmt, 2, [age UTF8String], -1,NULL);
}
if (sqlite3_step(stmt) != SQLITE_DONE) {
NSLog(@"插入记录数失败。%@",errorMsg);
}
sqlite3_finalize(stmt);
//
}
//删除记录数
+(void)deleteAllRecord {
//
char *errorMsg;
char *studentTable = "delete from student;";
if (sqlite3_exec (database, studentTable,NULL,NULL, &errorMsg) != SQLITE_OK) {
sqlite3_close(database);
NSLog(@"删除记录数失败。%@",errorMsg);
}
//
}
//查询数据数 sql = @"select * from student"
+(NSMutableArray *)selectRecordWidthSQL:(NSString *)sql {
NSMutableArray *arr=[[NSMutableArray alloc] init];
//
sqlite3_stmt *stmt;
if(sqlite3_prepare_v2(database, [sql UTF8String], -1, &stmt,nil) == SQLITE_OK){
while (sqlite3_step(stmt) == SQLITE_ROW) {
char *chmy_name = (char *)sqlite3_column_text(stmt,2); //第2个字段
char *chmy_age = (char *)sqlite3_column_text(stmt,3);
if (chmy_name!=nil) {
[arr addObject:[NSString stringWithUTF8String:chmy_name]];
}
if (chmy_age!=nil) {
[arr addObject:[NSString stringWithUTF8String:chmy_age]];
}
}
sqlite3_finalize(stmt);
}
//
return [arr autorelease];
}
@end