Java Doc for EmbedDatabaseMetaData.java in  » Database-DBMS » db-derby-10.2 » org » apache » derby » impl » jdbc » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Many of the methods here return lists of information in ResultSets. You can use the normal ResultSet methods such as getString and getInt to retrieve the data from these ResultSets. If a given form of metadata is not available, these methods should throw a SQLException.

Some of these methods take arguments that are String patterns. These arguments all have names such as fooPattern. Within a pattern String, "%" means match any substring of 0 or more characters, and "_" means match any one character. Only metadata entries matching the search pattern are returned. If a search pattern argument is set to a null ref, it means that argument's criteria should be dropped from the search.

A SQLException will be thrown if a driver does not support a meta data method. In the case of methods that return a ResultSet, either a ResultSet (which may be empty) is returned or a SQLException is thrown.

This implementation gets instructions from the Database for how to satisfy most requests for information. Each instruction is either a simple string containing the desired information, or the text of a query that may be executed on the database connection to gather the information. We get the instructions via an "InstructionReader," which requires the database Connection for initialization.

Those few pieces of metadata that are related to the driver, rather than the database, come from a separate InstructionReader. Note that in that case it probably doesn't make sense to allow an instruction to specify a query.
author:
   ames

Returns a list of the client info properties supported by the driver.

Only privileges matching the column name criteria are returned.

Only column descriptions matching the catalog, schema, table and column name criteria are returned.

Only descriptions matching the schema, procedure and parameter name criteria are returned.

Only procedure descriptions matching the schema and procedure name criteria are returned.

Get the schema names available in this database.

Only table descriptions matching the catalog, schema, table name and type criteria are returned.

If so, the SQL AS clause can be used to provide names for computed columns or to provide alias names for columns as required.

Each column description has the following columns:

1. SCOPE short => actual scope of result
   • bestRowTemporary - very temporary, while using row
   • bestRowTransaction - valid for remainder of current transaction
   • bestRowSession - valid for remainder of current session
2. COLUMN_NAME String => column name
3. DATA_TYPE int => SQL data type from java.sql.Types
4. TYPE_NAME String => Data source dependent type name
5. COLUMN_SIZE int => precision
6. BUFFER_LENGTH int => not used
7. DECIMAL_DIGITS short => scale
8. PSEUDO_COLUMN short => is this a pseudo column like an Oracle ROWID
   • bestRowUnknown - may or may not be pseudo column
   • bestRowNotPseudo - is NOT a pseudo column
   • bestRowPseudo - is a pseudo column

The catalog column is:

1. TABLE_CAT String => catalog name

Returns a list of the client info properties supported by the driver. The result set contains the following columns:

1. NAME String=> The name of the client info property.
2. MAX_LEN int=> The maximum length of the value for the property.
3. DEFAULT_VALUE String=> The default value of the property.
4. DESCRIPTION String=> A description of the property.

The ResultSet is sorted by the NAME column. A ResultSet object; each row is asupported client info property
exception:
  SQLException - if an error occurs

Only privileges matching the column name criteria are returned. They are ordered by COLUMN_NAME and PRIVILEGE.

Each privilige 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. GRANTOR => grantor of access (may be null)
6. GRANTEE String => grantee of access
7. PRIVILEGE String => name of access (SELECT, INSERT, UPDATE, REFRENCES, ...)
8. IS_GRANTABLE String => "YES" if grantee is permitted to grant to others; "NO" if not; null if unknown

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 int => 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.
19. SCOPE_CATLOG String => catalog of table that is the scope of a reference attribute (null if DATA_TYPE isn't REF)
20. SCOPE_SCHEMA String => schema of table that is the scope of a reference attribute (null if the DATA_TYPE isn't REF)
21. SCOPE_TABLE String => table name that this the scope of a reference attribure (null if the DATA_TYPE isn't REF)
22. SOURCE_DATA_TYPE short => source type of a distinct type or user-generated Ref type, SQL type from java.sql.Types (null if DATA_TYPE isn't DISTINCT or user-generated REF)
23. IS_AUTOINCREMENT String => Indicates whether this column is auto incremented
    • YES --- if the column is auto incremented
    • NO --- if the column is not auto incremented
    • empty string --- if it cannot be determined whether the column is auto incremented parameter is unknown

Each foreign key column description has the following columns:

1. PKTABLE_CAT String => primary key table catalog (may be null)
2. PKTABLE_SCHEM String => primary key table schema (may be null)
3. PKTABLE_NAME String => primary key table name
4. PKCOLUMN_NAME String => primary key column name
5. FKTABLE_CAT String => foreign key table catalog (may be null) being exported (may be null)
6. FKTABLE_SCHEM String => foreign key table schema (may be null) being exported (may be null)
7. FKTABLE_NAME String => foreign key table name being exported
8. FKCOLUMN_NAME String => foreign key column name being exported
9. KEY_SEQ short => sequence number within foreign key
10. UPDATE_RULE short => What happens to foreign key when primary is updated:
    • importedNoAction - do not allow update of primary key if it has been imported
    • importedKeyCascade - change imported key to agree with primary key update
    • importedKeySetNull - change imported key to NULL if its primary key has been updated
    • importedKeySetDefault - change imported key to default values if its primary key has been updated
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
11. DELETE_RULE short => What happens to the foreign key when primary is deleted.
    • importedKeyNoAction - do not allow delete of primary key if it has been imported
    • importedKeyCascade - delete rows that import a deleted key
    • importedKeySetNull - change imported key to NULL if its primary key has been deleted
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
    • importedKeySetDefault - change imported key to default if its primary key has been deleted
12. FK_NAME String => foreign key name (may be null)
13. PK_NAME String => primary key name (may be null)
14. DEFERRABILITY short => can the evaluation of foreign key constraints be deferred until commit
    • importedKeyInitiallyDeferred - see SQL92 for definition
    • importedKeyInitiallyImmediate - see SQL92 for definition
    • importedKeyNotDeferrable - see SQL92 for definition

Each foreign key column description has the following columns:

1. PKTABLE_CAT String => primary key table catalog (may be null)
2. PKTABLE_SCHEM String => primary key table schema (may be null)
3. PKTABLE_NAME String => primary key table name
4. PKCOLUMN_NAME String => primary key column name
5. FKTABLE_CAT String => foreign key table catalog (may be null) being exported (may be null)
6. FKTABLE_SCHEM String => foreign key table schema (may be null) being exported (may be null)
7. FKTABLE_NAME String => foreign key table name being exported
8. FKCOLUMN_NAME String => foreign key column name being exported
9. KEY_SEQ short => sequence number within foreign key
10. UPDATE_RULE short => What happens to foreign key when primary is updated:
    • importedNoAction - do not allow update of primary key if it has been imported
    • importedKeyCascade - change imported key to agree with primary key update
    • importedKeySetNull - change imported key to NULL if its primary key has been updated
    • importedKeySetDefault - change imported key to default values if its primary key has been updated
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
11. DELETE_RULE short => What happens to the foreign key when primary is deleted.
    • importedKeyNoAction - do not allow delete of primary key if it has been imported
    • importedKeyCascade - delete rows that import a deleted key
    • importedKeySetNull - change imported key to NULL if its primary key has been deleted
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
    • importedKeySetDefault - change imported key to default if its primary key has been deleted
12. FK_NAME String => foreign key name (may be null)
13. PK_NAME String => primary key name (may be null)
14. DEFERRABILITY short => can the evaluation of foreign key constraints be deferred until commit
    • importedKeyInitiallyDeferred - see SQL92 for definition
    • importedKeyInitiallyImmediate - see SQL92 for definition
    • importedKeyNotDeferrable - see SQL92 for definition

Compatibility: This is a new method in the API which is only available with with Derby versions > 10.1 and JDK versions >= 1.6

Upgrade: Since this is a new query it does not have an SPS, and will be available as soon as any database, new or old, is booted with the new version of Derby, (in soft and hard upgrade).
Parameters:
  catalog - limit the search to functions in this catalog(not used)
Parameters:
  schemaPattern - limit the search to functions in schemasmatching this pattern
Parameters:
  functionNamePattern - limit the search to functionsmatching this pattern
Parameters:
  parameterNamePattern - limit the search parametersmatching this pattern a ResultSet with metadata information
throws:
  SQLException - if a database error occurs

Compatibility: This is a new method in the API which is only available with with Derby versions > 10.1 and JDK versions >= 1.6

Upgrade: Since this is a new query it does not have an SPS, and will be available as soon as any database, new or old, is booted with the new version of Derby, (in soft and hard upgrade).
Parameters:
  catalog - limit the search to functions in this catalog (not used)
Parameters:
  schemaPattern - limit the search to functions in schemas matching this pattern
Parameters:
  functionNamePattern - limit the search to functions matching this pattern a ResultSet with metadata information
throws:
  SQLException - if any of the underlying jdbc methods fail

Each primary key column description has the following columns:

1. PKTABLE_CAT String => primary key table catalog being imported (may be null)
2. PKTABLE_SCHEM String => primary key table schema being imported (may be null)
3. PKTABLE_NAME String => primary key table name being imported
4. PKCOLUMN_NAME String => primary key column name being imported
5. FKTABLE_CAT String => foreign key table catalog (may be null)
6. FKTABLE_SCHEM String => foreign key table schema (may be null)
7. FKTABLE_NAME String => foreign key table name
8. FKCOLUMN_NAME String => foreign key column name
9. KEY_SEQ short => sequence number within foreign key
10. UPDATE_RULE short => What happens to foreign key when primary is updated:
    • importedNoAction - do not allow update of primary key if it has been imported
    • importedKeyCascade - change imported key to agree with primary key update
    • importedKeySetNull - change imported key to NULL if its primary key has been updated
    • importedKeySetDefault - change imported key to default values if its primary key has been updated
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
11. DELETE_RULE short => What happens to the foreign key when primary is deleted.
    • importedKeyNoAction - do not allow delete of primary key if it has been imported
    • importedKeyCascade - delete rows that import a deleted key
    • importedKeySetNull - change imported key to NULL if its primary key has been deleted
    • importedKeyRestrict - same as importedKeyNoAction (for ODBC 2.x compatibility)
    • importedKeySetDefault - change imported key to default if its primary key has been deleted
12. FK_NAME String => foreign key name (may be null)
13. PK_NAME String => primary key name (may be null)
14. DEFERRABILITY short => can the evaluation of foreign key constraints be deferred until commit
    • importedKeyInitiallyDeferred - see SQL92 for definition
    • importedKeyInitiallyImmediate - see SQL92 for definition
    • importedKeyNotDeferrable - see SQL92 for definition

Each index 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. NON_UNIQUE boolean => Can index values be non-unique? false when TYPE is tableIndexStatistic
5. INDEX_QUALIFIER String => index catalog (may be null); null when TYPE is tableIndexStatistic
6. INDEX_NAME String => index name; null when TYPE is tableIndexStatistic
7. TYPE short => index type:
   • tableIndexStatistic - this identifies table statistics that are returned in conjuction with a table's index descriptions
   • tableIndexClustered - this is a clustered index
   • tableIndexHashed - this is a hashed index
   • tableIndexOther - this is some other style of index
8. ORDINAL_POSITION short => column sequence number within index; zero when TYPE is tableIndexStatistic
9. COLUMN_NAME String => column name; null when TYPE is tableIndexStatistic
10. ASC_OR_DESC String => column sort sequence, "A" => ascending, "D" => descending, may be null if sort sequence is not supported; null when TYPE is tableIndexStatistic
11. CARDINALITY int => When TYPE is tableIndexStatistic, then this is the number of rows in the table; otherwise, it is the number of unique values in the index.
12. PAGES int => When TYPE is tableIndexStatisic then this is the number of pages used for the table, otherwise it is the number of pages used for the current index.
13. FILTER_CONDITION String => Filter condition, if any. (may be null)

Each primary key 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. KEY_SEQ short => sequence number within primary key
6. PK_NAME String => primary key name (may be null)

Only descriptions matching the schema, procedure and parameter name criteria are returned. They are ordered by PROCEDURE_SCHEM and PROCEDURE_NAME. Within this, the return value, if any, is first. Next are the parameter descriptions in call order. The column descriptions follow in column number order.

Each row in the ResultSet is a parameter description or column description with the following fields:

1. PROCEDURE_CAT String => procedure catalog (may be null)
2. PROCEDURE_SCHEM String => procedure schema (may be null)
3. PROCEDURE_NAME String => procedure name
4. COLUMN_NAME String => column/parameter name
5. COLUMN_TYPE Short => kind of column/parameter:
   • procedureColumnUnknown - nobody knows
   • procedureColumnIn - IN parameter
   • procedureColumnInOut - INOUT parameter
   • procedureColumnOut - OUT parameter
   • procedureColumnReturn - procedure return value
   • procedureColumnResult - result column in ResultSet
6. DATA_TYPE int => SQL type from java.sql.Types
7. TYPE_NAME String => SQL type name
8. PRECISION int => precision
9. LENGTH int => length in bytes of data
10. SCALE short => scale
11. RADIX short => radix
12. NULLABLE short => can it contain NULL?
    • procedureNoNulls - does not allow NULL values
    • procedureNullable - allows NULL values
    • procedureNullableUnknown - nullability unknown
13. REMARKS String => comment describing parameter/column
14. COLUMN_DEF String
15. SQL_DATA_TYPE int
16. SQL_DATETIME_SUB int
17. CHAR_OCTET_LENGTH int
18. ORDINAL_POSITION int
19. IS_NULLABLE String
20. SPECIFIC_NAME String

Note: Some databases may not return the column descriptions for a procedure. Additional columns beyond SPECIFIC_NAME can be defined by the database.
Parameters:
  catalog - a catalog name; "" retrieves those without acatalog; null means drop catalog name from the selection criteria
Parameters:
  schemaPattern - a schema name pattern; "" retrieves thosewithout a schema
Parameters:
  procedureNamePattern - a procedure name pattern
Parameters:
  columnNamePattern - a column name pattern ResultSet - each row is a stored procedure parameter orcolumn description
See Also:   EmbedDatabaseMetaData.getSearchStringEscape
exception:
  SQLException - thrown on failure.

Only procedure descriptions matching the schema and procedure name criteria are returned. They are ordered by PROCEDURE_SCHEM, and PROCEDURE_NAME.

Each procedure description has the the following columns:

1. PROCEDURE_CAT String => procedure catalog (may be null)
2. PROCEDURE_SCHEM String => procedure schema (may be null)
3. PROCEDURE_NAME String => procedure name
4. reserved for future use
5. reserved for future use
6. reserved for future use
7. REMARKS String => explanatory comment on the procedure
8. PROCEDURE_TYPE short => kind of procedure:
   • procedureResultUnknown - May return a result
   • procedureNoResult - Does not return a result
   • procedureReturnsResult - Returns a result
9. SPECIFIC_NAME String => The name which uniquely identifies this procedure within its schema (since JDBC 4.0)

The schema columns are:

1. TABLE_SCHEM String => schema name
2. TABLE_CATALOG String => catalog name (may be null)

Get the schema names available in this database. The results are ordered by schema name.

The schema columns are:

1. TABLE_SCHEM String => schema name
2. TABLE_CATALOG String => catalog name (may be null)

The '_' character represents any single character.

The '%' character represents any sequence of zero or more characters. the string used to escape wildcard characters

Only privileges matching the schema and table name criteria are returned. They are ordered by TABLE_SCHEM, TABLE_NAME, and PRIVILEGE.

Each privilige 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. GRANTOR => grantor of access (may be null)
5. GRANTEE String => grantee of access
6. PRIVILEGE String => name of access (SELECT, INSERT, UPDATE, REFRENCES, ...)
7. IS_GRANTABLE String => "YES" if grantee is permitted to grant to others; "NO" if not; null if unknown

The table type is:

1. TABLE_TYPE String => table type. Typical types are "TABLE", "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS", "SYNONYM".

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

Each table 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. TABLE_TYPE String => table type. Typical types are "TABLE", "VIEW", "SYSTEM TABLE", "GLOBAL TEMPORARY", "LOCAL TEMPORARY", "ALIAS", "SYNONYM".
5. REMARKS String => explanatory comment on the table
6. TYPE_CAT String => the types catalog (may be null)
7. TYPE_SCHEM String => the types schema (may be null)
8. TYPE_NAME String => type name (may be null)
9. SELF_REFERENCING_COL_NAME String => name of the designated "identifier" column of a typed table (may be null)
10. REF_GENERATION String => specifies how values in SELF_REFERENCING_COL_NAME are created. Values are "SYSTEM", "USER", "DERIVED". (may be null)

Note: Some databases may not return information for all tables.
Parameters:
  catalog - a catalog name; "" retrieves those without acatalog; null means drop catalog name from the selection criteria
Parameters:
  schemaPattern - a schema name pattern; "" retrieves thosewithout a schema
Parameters:
  tableNamePattern - a table name pattern
Parameters:
  types - a list of table types to include; null returns all types ResultSet - each row is a table description
See Also:   EmbedDatabaseMetaData.getSearchStringEscape
exception:
  SQLException - thrown on failure.

Each type description has the following columns:

1. TYPE_NAME String => Type name
2. DATA_TYPE int => SQL data type from java.sql.Types
3. PRECISION int => maximum precision
4. LITERAL_PREFIX String => prefix used to quote a literal (may be null)
5. LITERAL_SUFFIX String => suffix used to quote a literal (may be null)
6. CREATE_PARAMS String => parameters used in creating the type (may be null)
7. NULLABLE short => can you use NULL for this type?
   • typeNoNulls - does not allow NULL values
   • typeNullable - allows NULL values
   • typeNullableUnknown - nullability unknown
8. CASE_SENSITIVE boolean=> is it case sensitive?
9. SEARCHABLE short => can you use "WHERE" based on this type:
   • typePredNone - No support
   • typePredChar - Only supported with WHERE .. LIKE
   • typePredBasic - Supported except for WHERE .. LIKE
   • typeSearchable - Supported for all WHERE ..
10. UNSIGNED_ATTRIBUTE boolean => is it unsigned?
11. FIXED_PREC_SCALE boolean => can it be a money value?
12. AUTO_INCREMENT boolean => can it be used for an auto-increment value?
13. LOCAL_TYPE_NAME String => localized version of type name (may be null)
14. MINIMUM_SCALE short => minimum scale supported
15. MAXIMUM_SCALE short => maximum scale supported
16. SQL_DATA_TYPE int => unused
17. SQL_DATETIME_SUB int => unused
18. NUM_PREC_RADIX int => usually 2 or 10

Only types matching the catalog, schema, type name and type criteria are returned. They are ordered by DATA_TYPE, TYPE_SCHEM and TYPE_NAME. The type name parameter may be a fully qualified name. In this case, the catalog and schemaPattern parameters are ignored.

Each type description has the following columns:

1. TYPE_CAT String => the type's catalog (may be null)
2. TYPE_SCHEM String => type's schema (may be null)
3. TYPE_NAME String => type name
4. CLASS_NAME String => Java class name
5. DATA_TYPE String => type value defined in java.sql.Types. One of JAVA_OBJECT, STRUCT, or DISTINCT
6. REMARKS String => explanatory comment on the type
7. BASE_TYPE short => type code of the source type of a DISTINCT type or the type that implements the user-generated reference type of the SELF_REFERENCING_COLUMN of a structured type as defined in java.sql.Types (null if DATA_TYPE is not DISTINCT or not STRUCT with REFERENCE_GENERATION = USER_DEFINED)

Note: If the driver does not support UDTs then an empty result set is returned.
Parameters:
  catalog - a catalog name; "" retrieves those without acatalog; null means drop catalog name from the selection criteria
Parameters:
  schemaPattern - a schema name pattern; "" retrieves thosewithout a schema
Parameters:
  typeNamePattern - a type name pattern; may be a fully qualifiedname
Parameters:
  types - a list of user-named types to include (JAVA_OBJECT, STRUCT, or DISTINCT); null returns all types ResultSet - each row is a type description
exception:
  SQLException - if a database-access error occurs.

Each column description has the following columns:

1. SCOPE short => is not used
2. COLUMN_NAME String => column name
3. DATA_TYPE int => SQL data type from java.sql.Types
4. TYPE_NAME String => Data source dependent type name
5. COLUMN_SIZE int => precision
6. BUFFER_LENGTH int => length of column value in bytes
7. DECIMAL_DIGITS short => scale
8. PSEUDO_COLUMN short => is this a pseudo column like an Oracle ROWID
   • versionColumnUnknown - may or may not be pseudo column
   • versionColumnNotPseudo - is NOT a pseudo column
   • versionColumnPseudo - is a pseudo column

If so, the SQL AS clause can be used to provide names for computed columns or to provide alias names for columns as required. A JDBC-Compliant driver always returns true. true if so