sqlite 用法总结

最新推荐文章于 2022-05-31 21:14:03 发布

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本文详细介绍了如何创建数据库并执行SQL语句，包括错误处理和查询结果解析。

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创建数据库

NSArray *paths= NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *strPaths =  [documentsDirectory stringByAppendingPathComponent:databaseName];
    if (sqlite3_open([strPaths UTF8String], &database) != SQLITE_OK) {
        sqlite3_close(database);
        NSAssert(0, @"MBDataBase info:>>>>Failed to open databse");
    }

执行sql语句

if(sqlite3_exec(database, [sSql_userTable UTF8String], nil, nil, nil)!= SQLITE_OK)

解析查询结果：

const char *sql_select = [sSql_search_byID UTF8String];
    
    sqlite3_stmt *statement;
    statement = nil;
    if (sqlite3_prepare_v2(database, sql_select, -1, &statement, NULL) != SQLITE_OK) {
        NSLog(@"Error: failed to prepare statement with message:get channels.");
        return nil;
    }
    
    while (sqlite3_step(statement) == SQLITE_ROW) {
        char* c_result      = (char*) sqlite3_column_text(statement, 0);
}

返回查询行数:

int nRow, nColumn;
    char * errmsg = NULL;
    char **dbResult;
    int unReadMessageCount = -1;
    if (sqlite3_get_table(database, [sSql_unRead_byID UTF8String], &dbResult, &nRow, &nColumn, &errmsg) == SQLITE_OK) {
        NSLog(@">>>>nRow>>>%d，>>>>nColumn>>%d",nRow，nColumn);
        int result_count = atoi((const char*)dbResult[nColumn]);

    }