/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.jdbc;
import java.sql.ParameterMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import org.h2.command.CommandInterface;
import org.h2.expression.ParameterInterface;
import org.h2.message.DbException;
import org.h2.message.Trace;
import org.h2.message.TraceObject;
import org.h2.util.MathUtils;
import org.h2.value.DataType;
import org.h2.value.Value;
/**
* Information about the parameters of a prepared statement.
*/
public class JdbcParameterMetaData extends TraceObject implements
ParameterMetaData {
private final JdbcPreparedStatement prep;
private final int paramCount;
private final ArrayList<? extends ParameterInterface> parameters;
JdbcParameterMetaData(Trace trace, JdbcPreparedStatement prep,
CommandInterface command, int id) {
setTrace(trace, TraceObject.PARAMETER_META_DATA, id);
this.prep = prep;
this.parameters = command.getParameters();
this.paramCount = parameters.size();
}
/**
* Returns the number of parameters.
*
* @return the number
*/
@Override
public int getParameterCount() throws SQLException {
try {
debugCodeCall("getParameterCount");
checkClosed();
return paramCount;
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the parameter mode.
* Always returns parameterModeIn.
*
* @param param the column index (1,2,...)
* @return parameterModeIn
*/
@Override
public int getParameterMode(int param) throws SQLException {
try {
debugCodeCall("getParameterMode", param);
getParameter(param);
return parameterModeIn;
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the parameter type.
* java.sql.Types.VARCHAR is returned if the data type is not known.
*
* @param param the column index (1,2,...)
* @return the data type
*/
@Override
public int getParameterType(int param) throws SQLException {
try {
debugCodeCall("getParameterType", param);
ParameterInterface p = getParameter(param);
int type = p.getType();
if (type == Value.UNKNOWN) {
type = Value.STRING;
}
return DataType.getDataType(type).sqlType;
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the parameter precision.
* The value 0 is returned if the precision is not known.
*
* @param param the column index (1,2,...)
* @return the precision
*/
@Override
public int getPrecision(int param) throws SQLException {
try {
debugCodeCall("getPrecision", param);
ParameterInterface p = getParameter(param);
return MathUtils.convertLongToInt(p.getPrecision());
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the parameter scale.
* The value 0 is returned if the scale is not known.
*
* @param param the column index (1,2,...)
* @return the scale
*/
@Override
public int getScale(int param) throws SQLException {
try {
debugCodeCall("getScale", param);
ParameterInterface p = getParameter(param);
return p.getScale();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Checks if this is nullable parameter.
* Returns ResultSetMetaData.columnNullableUnknown..
*
* @param param the column index (1,2,...)
* @return ResultSetMetaData.columnNullableUnknown
*/
@Override
public int isNullable(int param) throws SQLException {
try {
debugCodeCall("isNullable", param);
return getParameter(param).getNullable();
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Checks if this parameter is signed.
* It always returns true.
*
* @param param the column index (1,2,...)
* @return true
*/
@Override
public boolean isSigned(int param) throws SQLException {
try {
debugCodeCall("isSigned", param);
getParameter(param);
return true;
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the Java class name of the parameter.
* "java.lang.String" is returned if the type is not known.
*
* @param param the column index (1,2,...)
* @return the Java class name
*/
@Override
public String getParameterClassName(int param) throws SQLException {
try {
debugCodeCall("getParameterClassName", param);
ParameterInterface p = getParameter(param);
int type = p.getType();
if (type == Value.UNKNOWN) {
type = Value.STRING;
}
return DataType.getTypeClassName(type);
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Returns the parameter type name.
* "VARCHAR" is returned if the type is not known.
*
* @param param the column index (1,2,...)
* @return the type name
*/
@Override
public String getParameterTypeName(int param) throws SQLException {
try {
debugCodeCall("getParameterTypeName", param);
ParameterInterface p = getParameter(param);
int type = p.getType();
if (type == Value.UNKNOWN) {
type = Value.STRING;
}
return DataType.getDataType(type).name;
} catch (Exception e) {
throw logAndConvert(e);
}
}
private ParameterInterface getParameter(int param) {
checkClosed();
if (param < 1 || param > paramCount) {
throw DbException.getInvalidValueException("param", param);
}
return parameters.get(param - 1);
}
private void checkClosed() {
prep.checkClosed();
}
/**
* Return an object of this class if possible.
*
* @param iface the class
* @return this
*/
@Override
@SuppressWarnings("unchecked")
public <T> T unwrap(Class<T> iface) throws SQLException {
try {
if (isWrapperFor(iface)) {
return (T) this;
}
throw DbException.getInvalidValueException("iface", iface);
} catch (Exception e) {
throw logAndConvert(e);
}
}
/**
* Checks if unwrap can return an object of this class.
*
* @param iface the class
* @return whether or not the interface is assignable from this class
*/
@Override
public boolean isWrapperFor(Class<?> iface) throws SQLException {
return iface != null && iface.isAssignableFrom(getClass());
}
/**
* INTERNAL
*/
@Override
public String toString() {
return getTraceObjectName() + ": parameterCount=" + paramCount;
}
}