1.创建数据库
- (void)viewDidLoad {
NSString *filename = [self dataFilePath];
NSLog(@"%@",filename);
if (sqlite3_open([filename UTF8String], &db) != SQLITE_OK) {
sqlite3_close(db);
NSAssert(NO,@"数据库打开失败。");
} else {
char *err;
NSString *createSQL = [NSString stringWithFormat:@"CREATE TABLE IF NOT EXISTS
%@ (%@ TEXT PRIMARY KEY, %@ TEXT, %@ TEXT);" ,
TABLE_NAME,FIELDS_NAME_SID,FIELDS_NAME_SNAME,FIELDS_NAME_SCLASS];
if (sqlite3_exec(db,[createSQL UTF8String],NULL,NULL,&err) != SQLITE_OK) {
sqlite3_close(db);
NSAssert1(NO, @"建表失败, %@", err);
}
sqlite3_close(db);
}
}
2.数据保存
-(IBAction) save {
NSString *filename = [self dataFilePath];
NSLog(@"%@",filename);
if (sqlite3_open([filename UTF8String], &db) != SQLITE_OK) {
sqlite3_close(db);
NSAssert(NO,@"数据库打开失败。");
} else {
NSString *sqlStr = [NSString stringWithFormat: @"INSERT OR REPLACE INTO %@ (%@, %@, %@) VALUES (?,?,?)",
TABLE_NAME, FIELDS_NAME_SID, FIELDS_NAME_SNAME, FIELDS_NAME_SCLASS];
sqlite3_stmt *statement;
//预处理过程
if (sqlite3_prepare_v2(db, [sqlStr UTF8String], -1, &statement, NULL) == SQLITE_OK) {
//绑定参数开始
sqlite3_bind_text(statement, 1, [studentId.text UTF8String], -1, NULL);
sqlite3_bind_text(statement, 2, [studentName.text UTF8String], -1, NULL);
sqlite3_bind_text(statement, 3, [studentClass.text UTF8String], -1, NULL);
//执行插入
if (sqlite3_step(statement) != SQLITE_DONE) {
NSAssert(0, @"插入数据失败。");
}
}
sqlite3_finalize(statement);
sqlite3_close(db);
}
}
3.查询数据
-(IBAction) load {
NSString *filename = [self dataFilePath];
NSLog(@"%@",filename);
if (sqlite3_open([filename UTF8String], &db) != SQLITE_OK) {
sqlite3_close(db);
NSAssert(NO,@"数据库打开失败。");
} else {
NSString *qsql = [NSString stringWithFormat: @"SELECT %@,%@,%@ FROM
%@ where %@ = ?", FIELDS_NAME_SID, FIELDS_NAME_SNAME,
FIELDS_NAME_SCLASS, TABLE_NAME,FIELDS_NAME_SID];
sqlite3_stmt *statement;
//预处理过程
if (sqlite3_prepare_v2(db, [qsql UTF8String], -1, &statement, NULL) == SQLITE_OK) {
//绑定参数开始
sqlite3_bind_text(statement, 1, "1000", -1, NULL);
while (sqlite3_step(statement) == SQLITE_ROW) {
char *field1 = (char *) sqlite3_column_text(statement, 0);
NSString *field1Str = [[NSString alloc] initWithUTF8String: field1];
studentId.text = field1Str;
char *field2 = (char *) sqlite3_column_text(statement, 1);
NSString *field2Str = [[NSString alloc] initWithUTF8String: field2];
studentName.text = field2Str;
char *field3 = (char *) sqlite3_column_text(statement, 2);
NSString *field3Str = [[NSString alloc] initWithUTF8String: field3];
studentClass.text = field3Str;
[field1Str release];
[field2Str release];
[field3Str release];
}
}
sqlite3_finalize(statement);
sqlite3_close(db);
}
}