In this short post, we are going to learn how to list all columns of every table in an Oracle database.
We want to get the name of the column, the name of the table it belongs to and the type of date for that column. Continue reading “Listing all columns from an Oracle database”
Oracle date format
Let’s review Oracle date formatting.
This is useful for functions like TO_DATE, TO_CHAR or alter session to modify nls_date_format. Continue reading “Oracle date format”
Oracle numeric format
Let’s take a look at the Oracle numeric format masks. Continue reading “Oracle numeric format”
The Oracle NULLIF function
The NULLIF function evaluates two expressions in the following way:
- If they are equal, it returns NULL.
- If they are not equal, it returns the first expression.
The Oracle NVL2 function
NVL2 provides a similar functionality as NVL function.
This function evaluates a column or expression in the following way:
- If the result is not NULL, it returns the second parameter that was given to NVL2 function.
- If the result is NULL, it returns the third parameter that was given to NVL2.
The Oracle NVL function
The NVL function evaluates a column or an expression this way:
- If it’s not NULL, it returns the evaluated value.
- If it’s NULL, it returns the indicated value in the second parameter of NVL.