代碼?：
首先導(dǎo)入頭文件(#import <sqlite3.h>)
#pragma mark ** 單例
+ (instancetype)shareDataBaseHandler {
// 在靜態(tài)區(qū), 只初始化一次.
static DataBaseHandler *dataBase = nil;
if (dataBase == nil) {
dataBase = [[DataBaseHandler alloc] init];
}
return dataBase;
}
#pragma mark ** 定義一個sqlite 結(jié)構(gòu)體(對象)
sqlite3 *db;
#pragma mark ** 打開數(shù)據(jù)庫
- (void)openDataBase {
// API: sqlite3_open.
if (db != nil) {
NSLog(@"數(shù)據(jù)庫已經(jīng)開啟!!!");
return;
}
// 文件路徑.
NSString *file = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"collect.sqlite"];
int result = sqlite3_open(file.UTF8String, &db);
if (result == SQLITE_OK) {
// NSLog(@"數(shù)據(jù)庫打開成功!");
} else {
NSLog(@"數(shù)據(jù)庫打開失敗, code = %d", result);
}
}
#pragma mark ** 創(chuàng)建表格
- (void)createTable {
// API: sqlite3_exec.
// 創(chuàng)建SQL 語句.
NSString *createTableSQL = @"CREATE TABLE IF NOT EXISTS model(number integer PRIMARY KEY AUTOINCREMENT, name text, photo text, id text)";
int result = sqlite3_exec(db, createTableSQL.UTF8String, NULL, NULL, nil);
if (result == SQLITE_OK) {
// NSLog(@"創(chuàng)建表格成功");
} else {
NSLog(@"表格創(chuàng)建失敗, code = %d", result);
}
}
#pragma mark ** 插入數(shù)據(jù)
- (void)insertModel:(ModelForTravels *)model {
// API: sqlite3_exec.
NSString *insertSQL = [NSString stringWithFormat:@"INSERT into model(name, photo, id) VALUES('%@', '%@', '%@')", model.name, model.front_cover_photo_url, model.id_count];
int result = sqlite3_exec(db, insertSQL.UTF8String, nil, nil, nil);
if (result == SQLITE_OK) {
} else {
}
}
#pragma mark ** 刪除數(shù)據(jù)
- (void)deleteWithName:(NSString *)name {
// API: sqlite3_exec.
NSString *deleteSQL = [NSString stringWithFormat:@"DELETE FROM model WHERE name = '%@'", name];
int result = sqlite3_exec(db, deleteSQL.UTF8String, nil, nil, nil);
if (result == SQLITE_OK) {
} else {
}
}
#pragma mark ** 查詢數(shù)據(jù)
- (NSMutableArray *)selectAllData {
// 存放符合條件的數(shù)據(jù)(元素是Model 對象).
NSMutableArray *array = [NSMutableArray array];
// sql 語句.
NSString *selectSQL = [NSString stringWithFormat:@"SELECT * FROM model"];
// API: stmt 結(jié)構(gòu)體, sqlite3_prepareV2, sqlite3_step, sqlite3_column.
// 聲明一個stmt 對象(結(jié)構(gòu)體).
sqlite3_stmt *stmt = nil;
int result = sqlite3_prepare_v2(db, selectSQL.UTF8String, -1, &stmt, nil);
if (result == SQLITE_OK) {
// 每行都執(zhí)行查詢語句.
while (sqlite3_step(stmt) == SQLITE_ROW) {
// 如果查詢條件匹配, 通過sqlite3_column (函數(shù)簇), 取出值.
// 取出哪一列的數(shù)據(jù).
const unsigned char *name = sqlite3_column_text(stmt, 1);
const unsigned char *photo = sqlite3_column_text(stmt, 2);
const unsigned char *id_count = sqlite3_column_text(stmt, 3);
// 創(chuàng)建Model 對象, 賦值之后放到數(shù)組中.
ModelForTravels *model = [[ModelForTravels alloc] init];
model.name = [NSString stringWithUTF8String:(const char *) name];
model.front_cover_photo_url = [NSString stringWithUTF8String:(const char *) photo];
model.id_count = [NSString stringWithUTF8String:(const char *) id_count];
[array insertObject:model atIndex:0];
}
// 銷毀對象.
sqlite3_finalize(stmt);
} else {
// 銷毀對象.
sqlite3_finalize(stmt);
}
return array;
}
#pragma mark ** 刪除表格
- (void)dropTable {
NSString *dropSQL = @"DROP TABLE model";
int result = sqlite3_exec(db, dropSQL.UTF8String, nil, nil, nil);
if (result == SQLITE_OK) {
} else {
}
}
#pragma mark ** 關(guān)閉數(shù)據(jù)庫
- (void)closeDB {
// API: sqlite3_close.
int result = sqlite3_close(db);
if (result == SQLITE_OK) {
db = nil;
} else {
}
}
