org.mariadb.jdbc.ParameterMetaData Maven / Gradle / Ivy
// SPDX-License-Identifier: LGPL-2.1-or-later
// Copyright (c) 2012-2014 Monty Program Ab
// Copyright (c) 2015-2021 MariaDB Corporation Ab
package org.mariadb.jdbc;
import java.sql.SQLException;
import org.mariadb.jdbc.client.ColumnDecoder;
import org.mariadb.jdbc.client.DataType;
import org.mariadb.jdbc.export.ExceptionFactory;
/** Parameter metadata */
public class ParameterMetaData implements java.sql.ParameterMetaData {
private final ColumnDecoder[] params;
private final ExceptionFactory exceptionFactory;
/**
* Constructor
*
* @param exceptionFactory exception factory
* @param params columns metadata
*/
protected ParameterMetaData(ExceptionFactory exceptionFactory, ColumnDecoder[] params) {
this.params = params;
this.exceptionFactory = exceptionFactory;
}
/**
* Retrieves the number of parameters in the PreparedStatement object for which this
* ParameterMetaData object contains information.
*
* @return the number of parameters
*/
@Override
public int getParameterCount() {
return params.length;
}
private void checkIndex(int index) throws SQLException {
if (index < 1 || index > params.length) {
throw new SQLException(
String.format(
"Wrong index position. Is %s but must be in 1-%s range", index, params.length));
}
}
/**
* Retrieves whether null values are allowed in the designated parameter.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return the nullability status of the given parameter; one of
* ParameterMetaData.parameterNoNulls, ParameterMetaData.parameterNullable
* @throws SQLException if wrong index
*/
@Override
public int isNullable(int idx) throws SQLException {
checkIndex(idx);
return java.sql.ParameterMetaData.parameterNullable;
}
/**
* Retrieves whether values for the designated parameter can be signed numbers.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if wrong index
*/
@Override
public boolean isSigned(int idx) throws SQLException {
checkIndex(idx);
return params[idx - 1].isSigned();
}
/**
* 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.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return precision
* @throws SQLException if wrong index
*/
@Override
public int getPrecision(int idx) throws SQLException {
checkIndex(idx);
return params[idx - 1].getPrecision();
}
/**
* 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. Parameter type are not sent by
* server. See * https://jira.mariadb.org/browse/CONJ-568 and
* https://jira.mariadb.org/browse/MDEV-15031
*
* @param idx the first parameter is 1, the second is 2, ...
* @return scale
* @throws SQLException if a database access error occurs
*/
@Override
public int getScale(int idx) throws SQLException {
checkIndex(idx);
return params[idx - 1].getDecimals();
}
/**
* Retrieves the designated parameter's SQL type. Parameter type are not sent by server. See
* https://jira.mariadb.org/browse/CONJ-568 and https://jira.mariadb.org/browse/MDEV-15031
*
* @param idx the first parameter is 1, the second is 2, ...
* @return SQL types from java.sql.Types
* @throws SQLException because not supported
*/
@Override
public int getParameterType(int idx) throws SQLException {
checkIndex(idx);
throw exceptionFactory.create("Getting parameter type metadata are not supported", "0A000", -1);
}
/**
* Retrieves the designated parameter's database-specific type name.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return 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 wrong index
*/
@Override
public String getParameterTypeName(int idx) throws SQLException {
checkIndex(idx);
// https://jira.mariadb.org/browse/XPT-279 Xpand can return wrong datatype for parameters
DataType type = params[idx - 1].getType();
return type == null ? null : type.name();
}
/**
* Retrieves the fully-qualified name of the Java class whose instances should be passed to the
* method PreparedStatement.setObject.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return 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 wrong index
*/
@Override
public String getParameterClassName(int idx) throws SQLException {
checkIndex(idx);
throw exceptionFactory.create("Unknown parameter metadata class name", "0A000");
}
/**
* Retrieves the designated parameter's mode.
*
* @param idx the first parameter is 1, the second is 2, ...
* @return mode of the parameter; one of ParameterMetaData.parameterModeIn,
* ParameterMetaData.parameterModeOut, or ParameterMetaData.parameterModeInOut
* ParameterMetaData.parameterModeUnknown.
*/
@Override
public int getParameterMode(int idx) throws SQLException {
checkIndex(idx);
return java.sql.ParameterMetaData.parameterModeIn;
}
/**
* 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 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.
*
* @param iface A Class defining an interface that the result must implement.
* @return an object that implements the interface. Maybe a proxy for the actual implementing
* object.
* @throws SQLException If no object found that implements the interface
*/
@Override
public T unwrap(Class iface) throws SQLException {
if (isWrapperFor(iface)) {
return iface.cast(this);
}
throw new SQLException("The receiver is not a wrapper for " + iface.getName());
}
/**
* 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.
*
* @param iface a Class defining an interface.
* @return true if this implements the interface or directly or indirectly wraps an object that
* does.
*/
@Override
public boolean isWrapperFor(Class iface) {
return iface.isInstance(this);
}
}