IPhone中SQLite3的使用

以下是一些SQLite3的基本操作，主要是写给自己温习，同时也希望能帮到像我一样的新手！

注意：要在工程中的Frameworks中导入相应的libsqlite3.dylib文件，也许在相应的目录下存在多个以libsqlite3开头的文件，务必选择libsqlite3.dylib，它始终指向最新版的SQLite3库的别名。

打开数据库：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *path = [documentsDirectory stringByAppendingPathComponent:@"database.sqlite"];//database.sqlite为自己定义数据库名称

    NSFileManager *fileManager = [NSFileManager defaultManager];

    databasePath_ = path;

    BOOL find = [fileManager fileExistsAtPath:path];

    if (!find) {		

		NSString *rePath = getBundleFilePath(@"database", @"sqlite");

		NSData *dataFile = [NSData dataWithContentsOfFile:rePath];

		[dataFile writeToFile:databasePath_ atomically:YES];

	}
	NSLog(@"Database file have already existed.");

	if(sqlite3_open([path UTF8String], &database_) != SQLITE_OK) {

		sqlite3_close(database_);

		NSLog(@"Error: open database file.");
	}

创建数据库：

NSString *creatSQL = @"CREATE TABLE IF NOT EXISTS FIELDS (ROW INTEGER PRIMARY KEY, FIELD_DATA TEXT);";

	if (sqlite3_exec(database, [creatSQL UTF8String], NULL, NULL, &errorMsg) != SQLITE_OK) {

		sqlite3_close(database);

		NSLog@"Error creating table");
	}

对表的操作，以查询为例

NSString *query = @"SELECT ROW, FIELD_DATA FROM FIELDS ";

sqlite3_stmt *statement;

	if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil) != SQLITE_OK) {
		while (sqlite3_step(statement) == SQLITE_ROW) {

			int row = sqlite3_column_int(statement, 0);//第一列

			char *rowData = (char *)sqlite3_column_text(statement, 1);//第二列
			
			NSString *fieldValue = [[NSString alloc] initWithUTF8String:rowData];
			
			[fieldValue release];
		}
		sqlite3_finalize(statement);
	}