set_column
Description:
Sets a new column/value pair to the given context this.
Column, must be a column in the given table's name setted by set_table
() (a table in the <link linkend="information_schema">database schema</link>). If the given column already exists it's
value is overwrited.
Column's name and value is copied and destroyed when free is called.
Parameters:
| this |
a MetaContext struct to add column/value pais to |
| column |
the column's name |
| value |
the column's value |
| cnc |
a Connection to be used when identifier are normalized, or NULL |