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Gets a description of table columns available in the specified catalog.
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:
TABLE_CAT
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String
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table catalog (may be null)
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TABLE_SCHEM
|
String
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table schema (may be null)
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TABLE_NAME
|
String
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table name
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COLUMN_NAME
|
String
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column name
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DATA_TYPE
|
Short
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SQL type from java.sql.Types
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TYPE_NAME
|
String
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Data source dependent type name, for a UDT the type name is fully qualified
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COLUMN_SIZE
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Int
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Column size. For char or date types this is the maximum number of characters, for numeric or decimal types this is precision.
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BUFFER_LENGTH
|
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is not used.
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DECIMAL_DIGITS
|
int
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the number of fractional digits
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NUM_PREC_RADIX
|
int
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Radix (typically either 10 or 2)
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NULLABLE
|
int
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is NULL allowed?
columnNoNulls - might not allow NULL values
columnNullable - definitely allows NULL values
columnNullableUnknown - nullability unknown
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REMARKS
|
String
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comment describing column (may be null)
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COLUMN_DEF
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String
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default value (may be null)
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SQL_DATA_TYPE
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int
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unused
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SQL_DATETIME_SUB
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int
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unused
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CHAR_OCTET_LENGTH
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int
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for char types the maximum number of bytes in the column
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ORDINAL_POSITION
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int
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index of column in table (starting at 1)
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IS_NULLABLE
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String
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"NO" means column definitely does not allow NULL values; "YES" means the column might allow NULL values. An empty string means nobody knows.
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Syntax
getColumns(string catalog,string schemaPattern,string tableNamePattern, string columnNamePattern)
Parameters
catalog
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The catalog that the procedure is in
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schemaPattern
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A schema name pattern
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tableNamePattern
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A table name pattern
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columnNamePattern
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A column name pattern
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If catalog is "" (the empty string), only procedures without a catalog are returned.
If catalog is the null value, catalog names are not part of the selection criteria.
If schemaPattern is "" (the empty string), only procedures without a schema are returned.
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