What is Table_catalog?
table_catalog. sql_identifier. Name of the database that contains the table (always the current database) table_schema.
What is INFORMATION_SCHEMA table?
Chapter 1 INFORMATION_SCHEMA Tables INFORMATION_SCHEMA provides access to database metadata, information about the MySQL server such as the name of a database or table, the data type of a column, or access privileges. Other terms that are sometimes used for this information are data dictionary and system catalog.
What is Table_catalog SQL Server?
In PostgreSQL, the table_catalog field actually means something. In fact, it is part of the SQL-92 standard. The catalog of a database groups related metadata for a database.
What does the alter table clause do?
ALTER TABLE is used to add, delete/drop or modify columns in the existing table. It is also used to add and drop various constraints on the existing table.
Which is the name of the schema table?
The name of the schema (database) to which the table containing the column belongs. The name of the table containing the column. The name of the column. The position of the column within the table. ORDINAL_POSITION is necessary because you might want to say ORDER BY ORDINAL_POSITION.
What are the columns of the table catalog?
It contains the following columns: Column Description TABLE_CATALOG Always contains the string ‘def’. TABLE_SCHEMA Database name. TABLE_NAME Table name. COLUMN_NAME Column name.
What is the name of the column in MySQL?
The COLUMNS table has these columns: The name of the catalog to which the table containing the column belongs. This value is always def . The name of the schema (database) to which the table containing the column belongs. The name of the table containing the column. The name of the column.
Is the table _ rows null for information _ schema tables?
TABLE_ROWS is NULL for INFORMATION_SCHEMA tables. For InnoDB tables, the row count is only a rough estimate used in SQL optimization. (This is also true if the InnoDB table is partitioned.) The average row length.