com.triactive.jdo.store.adapter
Class ColumnInfo

java.lang.Object
  com.triactive.jdo.store.adapter.CatalogInfo
      com.triactive.jdo.store.adapter.ColumnInfo

public class ColumnInfo

extends CatalogInfo

Represents the metadata of a specific table column. This class is basically a data structure that makes accessing the JDBC column metadata easier. Each of the items returned by DatabaseMetaData.getColumns(java.lang.String, java.lang.String, java.lang.String, java.lang.String) is represented by a public field in this class.

Subclasses of ColumnInfo can be created on a per-DBMS basis to supply missing metadata or correct faulty metadata obtained from that DBMS's JDBC driver(s).

Author:

Mike Martin

See Also:

DatabaseAdapter.newColumnInfo(java.sql.ResultSet), DatabaseMetaData.getColumns(java.lang.String, java.lang.String, java.lang.String, java.lang.String)

Field Summary

int	charOctetLength Indicates the maximum number of bytes in the column (for char types only).
java.lang.String	columnDef The default value for the column; may be null.
java.lang.String	columnName The column name.
int	columnSize Indicates the column size.
short	dataType Indicates the JDBC (SQL) data type from Types.
int	decimalDigits Indicates the number of fractional digits.
java.lang.String	isNullable Either "NO" indicating that the column definitely does not allow null values, "YES" indicating that the column might allow null values, or an empty string ("") indicating that nullability is unknown.
int	nullable Indicates whether the column can be NULL.
int	numPrecRadix Indicates the radix, which is typically either 10 or 2.
int	ordinalPosition Indicates the index of the column in its table; the first column is 1, the second column is 2, and so on.
java.lang.String	remarks An explanatory comment on the column; may be null.
java.lang.String	tableCat The table catalog, which may be null.
java.lang.String	tableName The table name.
java.lang.String	tableSchem The table schema, which may be null.
java.lang.String	typeName The local type name used by the data source.

Constructor Summary

ColumnInfo(java.sql.ResultSet rs)
Constructs a column information object from the current row of the given result set.

ColumnInfo(java.lang.String tableCat, java.lang.String tableSchem, java.lang.String tableName, java.lang.String columnName, short dataType, java.lang.String typeName, int columnSize, int decimalDigits, int numPrecRadix, int nullable, java.lang.String remarks, java.lang.String columnDef, int charOctetLength, int ordinalPosition, java.lang.String isNullable)
Constructs a column information object from its individual attributes.

Method Summary

boolean	equals(java.lang.Object obj) Indicates whether some object is "equal to" this one.
java.lang.String	getTableCatalog()
java.lang.String	getTableName()
java.lang.String	getTableSchema()
int	hashCode() Returns a hash code value for this object.
java.lang.String	toString() Returns the string representation of this object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

tableCat

public java.lang.String tableCat

The table catalog, which may be null.

tableSchem

public java.lang.String tableSchem

The table schema, which may be null.

tableName

public java.lang.String tableName

The table name.

columnName

public java.lang.String columnName

The column name.

dataType

public short dataType

Indicates the JDBC (SQL) data type from Types.

typeName

public java.lang.String typeName

The local type name used by the data source.

columnSize

public int columnSize

Indicates the column size. For char or date types, this is the maximum number of characters; for numeric or decimal types, this is the precision.

decimalDigits

public int decimalDigits

Indicates the number of fractional digits.

numPrecRadix

public int numPrecRadix

Indicates the radix, which is typically either 10 or 2.

nullable

public int nullable

Indicates whether the column can be NULL.

See Also:

DatabaseMetaData.columnNoNulls, DatabaseMetaData.columnNullable, DatabaseMetaData.columnNullableUnknown

remarks

public java.lang.String remarks

An explanatory comment on the column; may be null.

columnDef

public java.lang.String columnDef

The default value for the column; may be null.

charOctetLength

public int charOctetLength

Indicates the maximum number of bytes in the column (for char types only).

ordinalPosition

public int ordinalPosition

Indicates the index of the column in its table; the first column is 1, the second column is 2, and so on.

isNullable

public java.lang.String isNullable

Either "NO" indicating that the column definitely does not allow null values, "YES" indicating that the column might allow null values, or an empty string ("") indicating that nullability is unknown.

Constructor Detail

ColumnInfo

public ColumnInfo(java.sql.ResultSet rs)
           throws java.sql.SQLException

Constructs a column information object from the current row of the given result set. The ResultSet object passed must have been obtained from a call to DatabaseMetaData.getColumns().

This method only retrieves the values from the current row; the caller is required to advance to the next row with ResultSet.next().

Parameters:

rs - The result set returned from DatabaseMetaData.getColumns().

Throws:

java.sql.SQLException - if a column of column information could not be retrieved from the result set.

ColumnInfo

public ColumnInfo(java.lang.String tableCat,
                  java.lang.String tableSchem,
                  java.lang.String tableName,
                  java.lang.String columnName,
                  short dataType,
                  java.lang.String typeName,
                  int columnSize,
                  int decimalDigits,
                  int numPrecRadix,
                  int nullable,
                  java.lang.String remarks,
                  java.lang.String columnDef,
                  int charOctetLength,
                  int ordinalPosition,
                  java.lang.String isNullable)

Constructs a column information object from its individual attributes.

This can be useful to subclasses and/or custom DatabaseAdapters that need to modify and/or correct the metadata returned by the JDBC driver.

Method Detail

getTableCatalog

public java.lang.String getTableCatalog()

Specified by:

getTableCatalog in class CatalogInfo

getTableSchema

public java.lang.String getTableSchema()

Specified by:

getTableSchema in class CatalogInfo

getTableName

public java.lang.String getTableName()

Specified by:

getTableName in class CatalogInfo

equals

public final boolean equals(java.lang.Object obj)

Indicates whether some object is "equal to" this one. Two ColumnInfo objects are considered equal if their catalog, schema, table, and column names are all equal.

Parameters:

obj - the reference object with which to compare

Returns:

true if this object is equal to the obj argument; false otherwise.

hashCode

public final int hashCode()

Returns a hash code value for this object.

toString

public java.lang.String toString()

Returns the string representation of this object.