SQLite 是一個(gè)軟件庫(kù)，實(shí)現(xiàn)了自給自足的、無(wú)服務(wù)器的、零配置的、事務(wù)性的 SQL 數(shù)據(jù)庫(kù)引擎。SQLite 是在世界上最廣泛部署的 SQL 數(shù)據(jù)庫(kù)引擎。SQLite 源代碼不受版權(quán)限制。
@interface SQLiteManager : NSObject
+ (SQLiteManager *)shareSQL;
/**
* 打開(kāi)數(shù)據(jù)庫(kù)
*/
- (void)open;
/**
* 關(guān)閉數(shù)據(jù)庫(kù)
*/
- (void)close;
/**
* 創(chuàng)建表
*/
- (void)create;
/**
* 插入數(shù)據(jù)
*/
- (void)insert;
/**
* 查詢數(shù)據(jù)
*/
- (void)select;
/**
* 刪除數(shù)據(jù)
*/
- (void)deleteData;
@end
#import <sqlite3.h>
@interface SQLiteManager ()
{
sqlite3 *db;
}
@end
@implementation SQLiteManager
+ (SQLiteManager *)shareSQL {
static SQLiteManager *sqlManager = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sqlManager = [SQLiteManager new];
});
return sqlManager;
}
- (void)open {
//document存放路徑
NSString *documentPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
//sqlite路徑
NSString *sqlitePath = [documentPath stringByAppendingPathComponent:@"database.sqlite"];
/**
* 打開(kāi)數(shù)據(jù)庫(kù)
*
* @param UTF8String] [sqlitePath UTF8String] 把OC字符串轉(zhuǎn)成C字符串
* 如果不存在數(shù)據(jù)庫(kù)文件則會(huì)創(chuàng)建一個(gè)sqlite文件, 否則不創(chuàng)建, 直接打開(kāi)文件
*
* @return 打開(kāi)成功與失敗
*/
int result = sqlite3_open([sqlitePath UTF8String], &db);
if (result == SQLITE_OK) {
NSLog(@"打開(kāi)數(shù)據(jù)庫(kù)成功");
}else {
NSLog(@"打開(kāi)數(shù)據(jù)庫(kù)失敗");
}
}
- (void)close {
int result = sqlite3_close(db);
if (result == SQLITE_OK) {
NSLog(@"關(guān)閉數(shù)據(jù)庫(kù)成功");
}else {
NSLog(@"打開(kāi)數(shù)據(jù)庫(kù)失敗");
}
}
- (void)create {
NSString *sql = @"create table Person (id integer, name text)";
char *error = nil;
/**
* 執(zhí)行sql語(yǔ)句
* 1. 數(shù)據(jù)庫(kù)指針
* 2. 要執(zhí)行的SQL
* 3. callBack 執(zhí)行完SQL之后, 調(diào)用的C語(yǔ)言函數(shù)指針, 通常傳入nil
* 4. 第三個(gè)參數(shù)callBack的函數(shù)地址, 通常傳入nil
* 5. 錯(cuò)誤信息
*/
sqlite3_exec(db, sql.UTF8String, nil, nil, &error);
if (error == nil) {
NSLog(@"創(chuàng)建表成功");
}else {
NSLog(@"%s", error);
}
}
- (void)insert {
NSDate *time = [NSDate date];
NSLog(@"開(kāi)始插入數(shù)據(jù)");
NSLog(@"開(kāi)啟事務(wù)");
[self execSQL:@"BEGIN TRANSACTION"];
for (int i = 0; i < 100000; i++) {
NSString *sql = @"insert into Person values (0, '阿飛')";
if ([self execSQL:sql]) {
// NSLog(@"插入成功");
}else {
NSLog(@"插入失敗");
}
}
[self execSQL:@"COMMIT TRANSACTION"];
NSLog(@"結(jié)束");
NSLog(@"%f", [[NSDate date] timeIntervalSinceDate:time]);
}
- (void)select {
NSString *sql = @"select * from Person";
sqlite3_stmt * stmt = nil;
/**
* 預(yù)編譯sql
*
* @param db 數(shù)據(jù)庫(kù)
* @param sql.UTF8String sql語(yǔ)句
* @param -1 sql語(yǔ)句長(zhǎng)度, -1代表會(huì)自動(dòng)計(jì)算長(zhǎng)度
* @param stmt 數(shù)據(jù)庫(kù)管理的指針
* @param nil 預(yù)留參數(shù)
*
* @return 成功失敗
*/
int result = sqlite3_prepare_v2(db, sql.UTF8String, -1, &stmt, nil);
if (result == SQLITE_OK) {
//單步執(zhí)行, 并判斷是否有下一行數(shù)據(jù)
/**
* Person
*
* integer, name
* 0 '小明'
* 1 '小麗'
* 2 '小花'
*/
//while循環(huán)會(huì)去自動(dòng)循環(huán)每一條數(shù)據(jù),sqlite3_column_%, 回去自動(dòng)
while (sqlite3_step(stmt) == SQLITE_ROW) {
/**
* 獲取每列的數(shù)據(jù)
*
* @param stmt 數(shù)據(jù)庫(kù)指針
* @param 0 因?yàn)楸鞵erson有兩個(gè)字段, 就是兩列, 0代表第一列數(shù)據(jù), 1代表第二列數(shù)據(jù), 依次往后退
* @param sqlite3_column_count(); 獲取當(dāng)前查詢字段的個(gè)數(shù)
* @return 每一列,
*/
int count = sqlite3_column_count(stmt);
for (int i = 0; i < count; i++) {
//1 > 列名, 把C字符串轉(zhuǎn)成OC字符串
NSString *name = [[NSString alloc] initWithCString:sqlite3_column_name(stmt, i) encoding:NSUTF8StringEncoding];
//2 > 列對(duì)應(yīng)的數(shù)據(jù)類型
int type = sqlite3_column_type(stmt, i);
id objValue;
double doubleVaule;
NSInteger integerValue;
NSString *typeString;
switch (type) {
case SQLITE_FLOAT:
typeString = @"小數(shù)";
doubleVaule = sqlite3_column_double(stmt, i);
NSLog(@"name = %@, type = %@, value = %f", name, typeString, doubleVaule);
break;
case SQLITE3_TEXT:
typeString = @"字符串";
objValue = [NSString stringWithUTF8String:(const char *)sqlite3_column_text(stmt, i)];
NSLog(@"name = %@, type = %@, value = %@", name, typeString, objValue);
break;
case SQLITE_INTEGER:
typeString = @"整數(shù)";
integerValue = (NSInteger)sqlite3_column_int64(stmt, i);
NSLog(@"name = %@, type = %@, value = %ld", name, typeString, integerValue);
break;
case SQLITE_NULL:
typeString = @"空值";
objValue = [NSNull null];
NSLog(@"name = %@, type = %@, value = %@", name, typeString, objValue);
break;
default:
NSLog(@"不支持的數(shù)據(jù)類型");
break;
}
}
}
/**
* 釋放數(shù)據(jù)庫(kù)
*/
sqlite3_finalize(stmt);
}
}
- (void)deleteData {
NSString *sql = @"delete from Person where id = 0";
if ([self execSQL:sql]) {
NSLog(@"刪除數(shù)據(jù)成功");
}else {
NSLog(@"刪除數(shù)失敗");
}
}
- (BOOL)execSQL:(NSString *)sql {
char *error = nil;
sqlite3_exec(db, sql.UTF8String, nil, nil, &error);
if (error == nil) {
return YES;
}else {
NSLog(@"%s", error);
return NO;
}
}
/**
* 在SQLite數(shù)據(jù)庫(kù)操作中, 如果不顯示的開(kāi)啟事務(wù), 每一條數(shù)據(jù)庫(kù)的操作指令都會(huì)被開(kāi)啟事務(wù), 執(zhí)行完成之后, 提交事務(wù)
* 如果顯示的開(kāi)啟事務(wù), SQLite不再每次執(zhí)行數(shù)據(jù)庫(kù)開(kāi)啟一次事務(wù), 而是只開(kāi)啟一次.
* 因?yàn)槊看伍_(kāi)始,提交事務(wù)都會(huì)消耗資源, 如果頻繁的操作,會(huì)降低性能, 所以我們顯示的開(kāi)啟事務(wù)
*/
@end
