DatabaseMetaData.getColumns

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Syntax

Parameters

catalog

a catalog name; "" retrieves those without a catalog; null means drop catalog name from the selection criteria

schemaPattern

a schema name pattern; "" retrieves those without a schema

tableNamePattern

a table name pattern

columnNamePattern

a column name pattern

Returns

Description

Only column descriptions matching the catalog, schema, table and column name criteria are returned. They are ordered by TABLE_SCHEM, TABLE_NAME and ORDINAL_POSITION.

Each column description has the following columns:

1. TABLE_CAT String => table catalog (may be null)
2. TABLE_SCHEM String => table schema (may be null)
3. TABLE_NAME String => table name
4. COLUMN_NAME String => column name
5. DATA_TYPE short => SQL type from java.sql.Types
6. TYPE_NAME String => Data source dependent type name
7. COLUMN_SIZE int => column size. For char or date types this is the maximum number of characters, for numeric or decimal types this is precision.
8. BUFFER_LENGTH is not used.
9. DECIMAL_DIGITS int => the number of fractional digits
10. NUM_PREC_RADIX int => Radix (typically either 10 or 2)
11. NULLABLE int => is NULL allowed?
    • columnNoNulls - might not allow NULL values
    • columnNullable - definitely allows NULL values
    • columnNullableUnknown - nullability unknown
12. REMARKS String => comment describing column (may be null)
13. COLUMN_DEF String => default value (may be null)
14. SQL_DATA_TYPE int => unused
15. SQL_DATETIME_SUB int => unused
16. CHAR_OCTET_LENGTH int => for char types the maximum number of bytes in the column
17. ORDINAL_POSITION int => index of column in table (starting at 1)
18. IS_NULLABLE String => "NO" means column definitely does not allow NULL values; "YES" means the column might allow NULL values. An empty string means nobody knows.

Exceptions

See Also