org.hsqldb.jdbc
Class JDBCParameterMetaData

java.lang.Object
  org.hsqldb.jdbc.JDBCParameterMetaData

All Implemented Interfaces:

ParameterMetaData, Wrapper

public class JDBCParameterMetaData
extends Object
implements ParameterMetaData, Wrapper

An object that can be used to get information about the types and properties for each parameter marker in a PreparedStatement object. (JDBC4 Clarification:) For some queries and driver implementations, the data that would be returned by a ParameterMetaData object may not be available until the PreparedStatement has been executed.

Some driver implementations may not be able to provide information about the types and properties for each parameter marker in a CallableStatement object.

Since:

JDK 1.4, HSQLDB 1.7.2

Author:

Campbell Boucher-Burnet (boucherb@users dot sourceforge.net)

Field Summary

Fields inherited from interface java.sql.ParameterMetaData

parameterModeIn, parameterModeInOut, parameterModeOut, parameterModeUnknown, parameterNoNulls, parameterNullable, parameterNullableUnknown

Method Summary

String	getParameterClassName(int param) Retrieves the fully-qualified name of the Java class whose instances should be passed to the method PreparedStatement.setObject.
int	getParameterCount() Retrieves the number of parameters in the PreparedStatement object for which this ParameterMetaData object contains information.
int	getParameterMode(int param) Retrieves the designated parameter's mode.
int	getParameterType(int param) Retrieves the designated parameter's SQL type.
String	getParameterTypeName(int param) Retrieves the designated parameter's database-specific type name.
int	getPrecision(int param) Retrieves the designated parameter's specified column size.
int	getScale(int param) Retrieves the designated parameter's number of digits to right of the decimal point.
int	isNullable(int param) Retrieves whether null values are allowed in the designated parameter.
boolean	isSigned(int param) Retrieves whether values for the designated parameter can be signed numbers.
boolean	isWrapperFor(Class<?> iface) Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.
String	toString() Retrieves a String repsentation of this object.
<T> T	unwrap(Class<T> iface) Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

getParameterCount

public int getParameterCount()
                      throws SQLException

Retrieves the number of parameters in the PreparedStatement object for which this ParameterMetaData object contains information.

Specified by:

getParameterCount in interface ParameterMetaData

Returns:

the number of parameters

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

isNullable

public int isNullable(int param)
               throws SQLException

Retrieves whether null values are allowed in the designated parameter.

Specified by:

isNullable in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

the nullability status of the given parameter; one of ParameterMetaData.parameterNoNulls, ParameterMetaData.parameterNullable, or ParameterMetaData.parameterNullableUnknown

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

isSigned

public boolean isSigned(int param)
                 throws SQLException

Retrieves whether values for the designated parameter can be signed numbers.

Specified by:

isSigned in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

true if so; false otherwise

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

getPrecision

public int getPrecision(int param)
                 throws SQLException

Retrieves the designated parameter's specified column size.

The returned value represents the maximum column size for the given parameter. For numeric data, this is the maximum precision. For character data, this is the length in characters. For datetime datatypes, 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, this is the length in bytes. 0 is returned for data types where the column size is not applicable.

Specified by:

getPrecision in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

precision

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

getScale

public int getScale(int param)
             throws SQLException

Retrieves the designated parameter's number of digits to right of the decimal point. 0 is returned for data types where the scale is not applicable.

Specified by:

getScale in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

scale

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

getParameterType

public int getParameterType(int param)
                     throws SQLException

Retrieves the designated parameter's SQL type.

Specified by:

getParameterType in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

SQL type from java.sql.Types

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

See Also:

Types

getParameterTypeName

public String getParameterTypeName(int param)
                            throws SQLException

Retrieves the designated parameter's database-specific type name.

Specified by:

getParameterTypeName in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

type the name used by the database. If the parameter type is a user-defined type, then a fully-qualified type name is returned.

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

getParameterClassName

public String getParameterClassName(int param)
                             throws SQLException

Retrieves the fully-qualified name of the Java class whose instances should be passed to the method PreparedStatement.setObject.

Specified by:

getParameterClassName in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

the fully-qualified name of the class in the Java programming language that would be used by the method PreparedStatement.setObject to set the value in the specified parameter. This is the class name used for custom mapping.

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

getParameterMode

public int getParameterMode(int param)
                     throws SQLException

Retrieves the designated parameter's mode.

Specified by:

getParameterMode in interface ParameterMetaData

Parameters:

param - the first parameter is 1, the second is 2, ...

Returns:

mode of the parameter; one of ParameterMetaData.parameterModeIn, ParameterMetaData.parameterModeOut, or ParameterMetaData.parameterModeInOut ParameterMetaData.parameterModeUnknown.

Throws:

SQLException - if a database access error occurs

Since:

JDK 1.4, HSQLDB 1.7.2

unwrap

public <T> T unwrap(Class<T> iface)
         throws SQLException

Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy. If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the receiver is a wrapper and the wrapped object implements the interface then the result is the wrapped object or a proxy for the wrapped object. Otherwise return the the result of calling unwrap recursively on the wrapped object or a proxy for that result. If the receiver is not a wrapper and does not implement the interface, then an SQLException is thrown.

Specified by:

unwrap in interface Wrapper

Parameters:

iface - A Class defining an interface that the result must implement.

Returns:

an object that implements the interface. May be a proxy for the actual implementing object.

Throws:

SQLException - If no object found that implements the interface

Since:

JDK 1.6, HSQLDB 2.0

isWrapperFor

public boolean isWrapperFor(Class<?> iface)
                     throws SQLException

Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does. Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result of recursively calling isWrapperFor on the wrapped object. If this does not implement the interface and is not a wrapper, return false. This method should be implemented as a low-cost operation compared to unwrap so that callers can use this method to avoid expensive unwrap calls that may fail. If this method returns true then calling unwrap with the same argument should succeed.

Specified by:

isWrapperFor in interface Wrapper

Parameters:

iface - a Class defining an interface.

Returns:

true if this implements the interface or directly or indirectly wraps an object that does.

Throws:

SQLException - if an error occurs while determining whether this is a wrapper for an object with the given interface.

Since:

JDK 1.6, HSQLDB 2.0

toString

public String toString()

Retrieves a String repsentation of this object.

Overrides:

toString in class Object

Returns:

a String repsentation of this object