Posts tagged with sql:

MySQL, MariaDB, SQLite, PostgreSQL, Oracle, MS SQL, DB2 - differenceWhat is the difference between MySQL, MariaDB, SQLite, PostgreSQL, Oracle, MS SQL and IBM DB2 ? Which one is better than the other ? Do they work with regular SQL language ?

Difference between Fetch_assoc, Fetch_array, Fetch_row - MySQLWhat is the difference between Fetch_assoc, Fetch_array and Fetch_row in MySQL. When is it effective to use each of them ?

Error: You can't specify target table for update in FROM clauseI am receiving the following error notification when I try to use SQL INSERT and SELECT together: You can't specify target table 'items' for update in FROM...

Error: Illegal parameter data types INT and row for operation '='I am trying to use SELECT in SELECT in SQL query, to count the matches, but I am getting SQL error: Illegal parameter data types INT and row for operation '=' What...

Fix error: mysqli_select_db / query expects 2 arguments, 1 givenI have upgraded MySQL to a higher version, but I am getting an error: Fatal error: Uncaught ArgumentCountError: mysqli_select_db() expects exactly 2 arguments, 1 given How...

SQL to calculate total balance amount of each owner - debit/creditHow should the SQL Select look like, if I need to get the total account balance for each customer, from debit and credit transactions ? Table looks like: Transaction ID,...

Fatal error: Call to undefined function mysql_query() - PHPOn my new hosting, when I try to get the data from MySQL database with SELECT statement, the following error notification appears: Fatal error: Uncaught Error: Call to...

Impact of condition order in SQL WHERE clause on performanceDoes the order of condition in SQL WHERE clause affect the performance ? Is it possible to make SQL faster by changing of condition order ?

Is faster one big SQL query or multiple small SQL queries ?I need to optimize the SQL queries to make them faster. Is it better to run one big query or more small queries ?

Optimize SQL query to make it more faster - SQL query optimizationHow can I optimize SQL queries to make them run more faster ? What are the best methods for SQL query optimization ?