How many among the following use NULL to indicate failure?mysql_init(), mysql_real_connect()

Quiz on MySQL system and session only system variables, status and user defined variables. In MySQL Workbench, you can view the system and status variables by clicking Status and System Variables under the Management tab in the left navigation pane. The Status and System Variables screen lists all server variables for the MySQL connection. You can copy all variables to your clipboard, or use the search function to filter the variables.  You can also change system variables in MySQL Workbench by following these steps: Open the Administration tab Select the Status and System Variables... Show more

Quiz on MySQL system and session only system variables, status and user defined variables.

In MySQL Workbench, you can view the system and status variables by clicking Status and System Variables under the Management tab in the left navigation pane. The Status and System Variables screen lists all server variables for the MySQL connection. You can copy all variables to your clipboard, or use the search function to filter the variables. 

You can also change system variables in MySQL Workbench by following these steps:
Open the Administration tab
Select the Status and System Variables secondary tab
Select the Persist check box next to the variable name
Right-click a variable and choose a custom group 

You can also use the SHOW VARIABLES command to return a list of variables. You can filter the list using the LIKE operator. 

MySQL has three types of variables: user-defined, local, and system.
User-defined variables: Can be used in any part of the SQL query
Local variables: Can be used in the specific blocks of code only
System variables: Are already predefined by MySQL 

You can set most system variables at server startup using options on the command line or in an option file. You can also change most system variables dynamically at runtime using the SET statement.

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