Module org.tquadrat.foundation.sql

Package org.tquadrat.foundation.sql

Interface ParameterMetaData

All Known Implementing Classes:

EnhancedPreparedStatementBase.ParameterMetaDataImpl, ParameterMetaDataBase

@ClassVersion(sourceVersion="$Id: ParameterMetaData.java 1075 2023-10-02 12:37:07Z tquadrat $")
@API(status=STABLE,
     since="0.1.0")
public sealed interface ParameterMetaData
permits ParameterMetaDataBase

An instance of an implementation of this interface can be used to get information about the types and properties for each named parameter in an EnhancedPreparedStatement instance. For some queries and driver implementations, the data that would be returned by a ParameterMetaData object may not be available until the EnhancedPreparedStatement has been executed.

Each named parameter for an EnhancedPreparedStatement can be applied to the underlying PreparedStatement multiple times, for multiple parameter markers. The assumption is that the features are the same for all occurrences. Only for the nullability, all occurrences will be checked.

Author:

Thomas Thrien (thomas.thrien@tquadrat.org)

Version:

$Id: ParameterMetaData.java 1075 2023-10-02 12:37:07Z tquadrat $

Since:

0.1.0

See Also:

• ParameterMetaData

UML Diagram

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UML Diagram for "org.tquadrat.foundation.sql.ParameterMetaData"

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Method Summary

Modifier and Type	Method	Description
String	getParameterClassName(String parameterName)	Retrieves the fully-qualified name of the Java class whose instances should be passed to the method EnhancedPreparedStatement.setObject(String, Object).
int	getParameterCount()	Retrieves the number of parameters in the EnhancedPreparedStatement object for which this ParameterMetaData object contains information.
int[]	getParameterIndexes(String parameterName)	Retrieves the parameter indexes for the given parameter name.
Collection<String>	getParameterNames()	Retrieves the names of the parameters in the EnhancedPreparedStatement object for which this ParameterMetaData object contains information.
SQLType	getParameterType(String parameterName)	Retrieves the designated parameter's SQL type.
String	getParameterTypeName(String parameterName)	Retrieves the designated parameter's database-specific type name.
int	getPrecision(String parameterName)	Retrieves the designated parameter's specified column size.
int	getScale(String parameterName)	Retrieves the designated parameter's number of digits to right of the decimal point.
int	isNullable(String parameterName)	Retrieves whether NULL values are allowed in the designated parameter.
boolean	isSigned(String parameterName)	Retrieves whether values for the designated parameter can be signed numbers.

Method Details

getParameterClassName

String getParameterClassName(String parameterName)
                      throws SQLException

Retrieves the fully-qualified name of the Java class whose instances should be passed to the method EnhancedPreparedStatement.setObject(String, Object).

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

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

Throws:

SQLException - A database access error occurred.

getParameterCount

int getParameterCount()
               throws SQLException

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

Returns:

The number of parameters.

Throws:

SQLException - A database access error occurred.

getParameterIndexes

int[] getParameterIndexes(String parameterName)
                   throws SQLException

Retrieves the parameter indexes for the given parameter name.

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

The parameter indexes for this parameter name.

Throws:

SQLException - The given parameter name is not defined.

getParameterNames

Collection<String> getParameterNames()

Retrieves the names of the parameters in the EnhancedPreparedStatement object for which this ParameterMetaData object contains information.

Returns:

The names of the parameters.

getParameterType

SQLType getParameterType(String parameterName)
                  throws SQLException

Retrieves the designated parameter's SQL type.

Different from ParameterMetaData.getParameterType(int) will this method return an instance of SQLType for the type, and not an integer.

If the numerical value (as defined in Types) is required, it can be obtained like this:

  …
  int sqlType = getParameterType( param ).getVendorTypeNumber().intValue();
  …

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

The SQL type.

Throws:

SQLException - A database access error occurred.

See Also:

• JDBCType

getParameterTypeName

String getParameterTypeName(String parameterName)
                     throws SQLException

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

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

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

Throws:

SQLException - A database access error occurred.

getPrecision

int getPrecision(String parameterName)
          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 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, this is the length in bytes. 0 is returned for data types where the column size is not applicable.

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

The precision.

Throws:

SQLException - A database access error occurred.

getScale

int getScale(String parameterName)
      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.

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

The scale.

Throws:

SQLException - A database access error occurred.

isNullable

int isNullable(String parameterName)
        throws SQLException

Retrieves whether NULL values are allowed in the designated parameter.

If the parameter with the the given name is used multiple times in the underlying PreparedStatement, this method returns 2 when the nullability status is not the same for all uses.

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

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

Throws:

SQLException - A database access error occurs

isSigned

boolean isSigned(String parameterName)
          throws SQLException

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

Parameters:

parameterName - The name of the parameter, prefixed by a colon.

Returns:

true if a value can be a signed number, false otherwise.

Throws:

SQLException - A database access error occurred.