What is the %TYPE attribute?

What is the %TYPE attribute?

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When a PL/SQL variable is declared to hold column values, it must be ensured that the variable is of the correct datatype and precision. If not, a PL/SQL error occurs during execution. Rather than explicitly specifying the datatype and precision of a variable, the %TYPE attribute can be used to declare a variable according to another previously declared variable or database column.

The %TYPE attribute is generally used when the value stored in the variable will be derived from a table in the database. In order to use the %TYPE attribute in place of the datatype that is required in the variable declaration, the attribute is prefixed with the table name and column name. If referring to a previously declared variable, the attribute is prefixed with the name of the variable.

When a PL/SQL block consisting of such variables is compiled, the PL/SQL determines the datatype and size of the variables in order to ensure that such variables are always compatible with the column that is used to populate it. This is a definite advantage for writing and maintaining code because there is no need to be concerned about column datatype changes made at the database level.

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