com.ing.data.cassandra.jdbc.metadata

Class TypeMetadataResultSetBuilder

java.lang.Object

com.ing.data.cassandra.jdbc.metadata.AbstractMetadataResultSetBuilder

com.ing.data.cassandra.jdbc.metadata.TypeMetadataResultSetBuilder

public class TypeMetadataResultSetBuilder
extends AbstractMetadataResultSetBuilder

Utility class building metadata result sets (CassandraMetadataResultSet objects) related to types.

Constructor Summary

Constructors

Constructor and Description
TypeMetadataResultSetBuilder(CassandraStatement statement) Constructor.

Method Summary

Modifier and Type	Method and Description
CassandraMetadataResultSet	buildAttributes(String schemaPattern, String typeNamePattern, String attributesNamePattern) Builds a valid result set of the description of the given attribute of the given type for a user-defined type (UDT) that is available in the given schema.
CassandraMetadataResultSet	buildTypes(String databaseVersion) Builds a valid result set of all the data types supported by this database.
CassandraMetadataResultSet	buildUDTs(String schemaPattern, String typeNamePattern, int[] types) Builds a valid result set of the description of the user-defined types (UDTs) defined in a particular schema.

Methods inherited from class com.ing.data.cassandra.jdbc.metadata.AbstractMetadataResultSetBuilder

matchesPattern

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TypeMetadataResultSetBuilder

public TypeMetadataResultSetBuilder(CassandraStatement statement)
                             throws SQLException

Constructor.

Parameters:

statement - The statement.

Throws:

SQLException - if a database access error occurs or this statement is closed.

Method Detail

buildUDTs

public CassandraMetadataResultSet buildUDTs(String schemaPattern,
                                            String typeNamePattern,
                                            int[] types)
                                     throws SQLException

Builds a valid result set of the description of the user-defined types (UDTs) defined in a particular schema. This method is used to implement the method DatabaseMetaData.getUDTs(String, String, String, int[]).

Schema-specific UDTs in a Cassandra database will be considered as having type JAVA_OBJECT.

Only types matching the catalog, schema, type name and type criteria are returned. They are ordered by DATA_TYPE, TYPE_CAT, TYPE_SCHEM and TYPE_NAME. The type name parameter may be a fully-qualified name (it should respect the format <SCHEMA_NAME>.<TYPE_NAME>). In this case, the catalog and schemaPattern parameters are ignored.

The columns of this result set are:

1. TYPE_CAT String => type's catalog, may be null: here is the Cassandra cluster name (if available).
2. TYPE_SCHEM String => type's schema, may be null: here is the keyspace the type is member of.
3. TYPE_NAME String => user-defined type name.
4. CLASS_NAME String => Java class name, always UdtValue in the current implementation.
5. DATA_TYPE int => type value defined in Types. One of Types.JAVA_OBJECT, Types.STRUCT, or Types.DISTINCT. Always Types.JAVA_OBJECT in the current implementation.
6. REMARKS String => explanatory comment on the type, always empty in the current implementation.
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 Types (null if DATA_TYPE is not DISTINCT or not STRUCT with REFERENCE_GENERATION = USER_DEFINED). Always null in the current implementation.

Parameters:

schemaPattern - A schema pattern name; must match the schema name as it is stored in the database; "" retrieves those without a schema (will always return an empty set); null means that the schema name should not be used to narrow the search and in this case the search is restricted to the current schema (if available).

typeNamePattern - A type name pattern; must match the type name as it is stored in the database (not case-sensitive); may be a fully qualified name.

types - A list of user-defined types (Types.JAVA_OBJECT, Types.STRUCT, or Types.DISTINCT) to include; null returns all types. All the UDTs defined in a Cassandra database are considered as Types.JAVA_OBJECT, so other values will return an empty result set.

Returns:

A valid result set for implementation of DatabaseMetaData.getUDTs(String, String, String, int[]).

Throws:

SQLException - when something went wrong during the creation of the result set.

buildTypes

public CassandraMetadataResultSet buildTypes(String databaseVersion)
                                      throws SQLException

Builds a valid result set of all the data types supported by this database. This method is used to implement the method DatabaseMetaData.getTypeInfo().

They are ordered by DATA_TYPE and then by how closely the data type maps to the corresponding JDBC SQL type.

The Cassandra database does not support SQL distinct types. The information on the individual structured types (considered as Types.JAVA_OBJECT, not Types.STRUCT) may be obtained from the getUDTs() method.

The columns of this result set are:

1. TYPE_NAME String => type name.
2. DATA_TYPE int => SQL data type from 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:
   • DatabaseMetaData.typeNoNulls - does not allow NULL values
   • DatabaseMetaData.typeNullable - allows NULL values
   • DatabaseMetaData.typeNullableUnknown - nullability unknown
8. CASE_SENSITIVE boolean => is it case sensitive.
9. SEARCHABLE short => can you use "WHERE" based on this type:
   • DatabaseMetaData.typePredNone - no support
   • DatabaseMetaData.typePredChar - only supported with WHERE .. LIKE
   • DatabaseMetaData.typePredBasic - supported except for WHERE .. LIKE
   • DatabaseMetaData.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. Always false since Cassandra does not support auto-increment.
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 => not used.
17. SQL_DATETIME_SUB int => not used.
18. NUM_PREC_RADIX int => precision radix (typically either 10 or 2).

The PRECISION column represents the maximum column size that the server supports for the given datatype. For numeric data, this is the maximum precision. For character data, this is the length in characters. For datetime data types, this is the length in characters of the String representation (assuming the maximum allowed precision of the fractional seconds component). For binary data, this is the length in bytes. For the ROWID datatype (not supported by Cassandra), this is the length in bytes. The value null is returned for data types where the column size is not applicable.

Parameters:

databaseVersion - The database version the driver is currently connected to.

Returns:

A valid result set for implementation of DatabaseMetaData.getTypeInfo().

Throws:

SQLException - when something went wrong during the creation of the result set.

buildAttributes

public CassandraMetadataResultSet buildAttributes(String schemaPattern,
                                                  String typeNamePattern,
                                                  String attributesNamePattern)
                                           throws SQLException

Builds a valid result set of the description of the given attribute of the given type for a user-defined type (UDT) that is available in the given schema. This method is used to implement the method DatabaseMetaData.getAttributes(String, String, String, String).

Only descriptions for attributes of UDTs matching the catalog, schema, type and attribute criteria are returned. They are ordered by TYPE_CAT, TYPE_SCHEM and TYPE_NAME and ORDINAL_POSITION. This description does not contain inherited attributes. The type name parameter may be a fully-qualified name (it should respect the format <SCHEMA_NAME>.<TYPE_NAME>). In this case, the catalog and schemaPattern parameters are ignored.

The columns of this result set are:

1. TYPE_CAT String => table catalog, may be null: here is the Cassandra cluster name (if available).
2. TYPE_SCHEM String => table schema, may be null: here is the keyspace the type is member of.
3. TYPE_NAME String => type name.
4. ATTR_NAME String => attribute name.
5. DATA_TYPE int => attribute SQL type from Types.
6. ATTR_TYPE_NAME String => the data source dependent type name. For a UDT, the type name is fully qualified. There is no REF in Cassandra.
7. ATTR_SIZE int => column size.
8. DECIMAL_DIGITS int => the number of fractional digits, null is returned for data types where it is not applicable. Always null here.
9. NUM_PREC_RADIX int => Radix (typically either 10 or 2).
10. NULLABLE int => is NULL allowed:
    • DatabaseMetaData.attributeNoNulls - might not allow NULL values
    • DatabaseMetaData.attributeNullable - definitely allows NULL values
    • DatabaseMetaData.attributeNullableUnknown - nullability unknown
    Always DatabaseMetaData.attributeNoNulls here.
11. REMARKS String => comment describing column, may be null: always null here since comments on columns does not exist in Cassandra.
12. ATTR_DEF String => attribute default value, always null since Cassandra does not support default values.
13. SQL_DATA_TYPE int => is not used: always null here.
14. SQL_DATETIME_SUB int => is not used: always null here.
15. CHAR_OCTET_LENGTH int => for char types the maximum number of bytes in the column.
16. ORDINAL_POSITION int => index of attribute in UDT (starting at 1).
17. IS_NULLABLE String => ISO rules are used to determine the nullability for an attribute:
    • YES - if the attribute can include NULLs
    • NO - if the attribute cannot include NULLs
    • empty string - if the nullability for the attribute is unknown
    Always empty here.
18. SCOPE_CATALOG String => catalog of table that is the scope of a reference attribute (null if DATA_TYPE isn't REF). Always null here.
19. SCOPE_SCHEMA String => schema of table that is the scope of a reference attribute (null if DATA_TYPE isn't REF). Always null here.
20. SCOPE_TABLE String => table name that is the scope of a reference attribute (null if DATA_TYPE isn't REF). Always null here.
21. SOURCE_DATA_TYPE short => source type of a distinct type or user-generated Ref type, SQL type from Types (null if DATA_TYPE isn't DISTINCT or user-generated REF). Always null here.

Parameters:

schemaPattern - A schema pattern name; must match the schema name as it is stored in the database; "" retrieves those without a schema (will always return an empty set); null means that the schema name should not be used to narrow the search and in this case the search is restricted to the current schema (if available).

typeNamePattern - A type name pattern; must match the type name as it is stored in the database (not case-sensitive); may be a fully qualified name.

attributesNamePattern - An attribute name pattern; must match the attribute name as it is declared in the database (not case-sensitive).

Returns:

A valid result set for implementation of DatabaseMetaData.getAttributes(String, String, String, String).

Throws:

SQLException - when something went wrong during the creation of the result set.