org.mariadb.jdbc.MariaDbResultSetMetaData Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of mariadb-java-client Show documentation
Show all versions of mariadb-java-client Show documentation
JDBC driver for MariaDB and MySQL
/*
*
* MariaDB Client for Java
*
* Copyright (c) 2012-2014 Monty Program Ab.
* Copyright (c) 2015-2020 MariaDB Corporation Ab.
*
* This library is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License along
* with this library; if not, write to Monty Program Ab [email protected].
*
*/
package org.mariadb.jdbc;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Types;
import org.mariadb.jdbc.internal.ColumnType;
import org.mariadb.jdbc.internal.com.read.resultset.ColumnDefinition;
import org.mariadb.jdbc.internal.util.constant.ColumnFlags;
import org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory;
import org.mariadb.jdbc.util.Options;
public class MariaDbResultSetMetaData implements ResultSetMetaData {
private final ColumnDefinition[] fieldPackets;
private final Options options;
private final boolean forceAlias;
/**
* Constructor.
*
* @param fieldPackets column informations
* @param options connection options
* @param forceAlias force table and column name alias as original data
*/
public MariaDbResultSetMetaData(
final ColumnDefinition[] fieldPackets, final Options options, final boolean forceAlias) {
this.fieldPackets = fieldPackets;
this.options = options;
this.forceAlias = forceAlias;
}
/**
* Returns the number of columns in this ResultSet object.
*
* @return the number of columns
*/
public int getColumnCount() {
return fieldPackets.length;
}
/**
* Indicates whether the designated column is automatically numbered.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs
*/
public boolean isAutoIncrement(final int column) throws SQLException {
return (getColumnInformation(column).getFlags() & ColumnFlags.AUTO_INCREMENT) != 0;
}
/**
* Indicates whether a column's case matters.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs
*/
public boolean isCaseSensitive(final int column) throws SQLException {
return (getColumnInformation(column).getFlags() & ColumnFlags.BINARY_COLLATION) != 0;
}
/**
* Indicates whether the designated column can be used in a where clause.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
*/
public boolean isSearchable(final int column) {
return true;
}
/**
* Indicates whether the designated column is a cash value.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
*/
public boolean isCurrency(final int column) {
return false;
}
/**
* Indicates the nullability of values in the designated column.
*
* @param column the first column is 1, the second is 2, ...
* @return the nullability status of the given column; one of columnNoNulls,
* columnNullable or columnNullableUnknown
* @throws SQLException if a database access error occurs
*/
public int isNullable(final int column) throws SQLException {
if ((getColumnInformation(column).getFlags() & ColumnFlags.NOT_NULL) == 0) {
return ResultSetMetaData.columnNullable;
} else {
return ResultSetMetaData.columnNoNulls;
}
}
/**
* Indicates whether values in the designated column are signed numbers.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs
*/
public boolean isSigned(int column) throws SQLException {
return getColumnInformation(column).isSigned();
}
/**
* Indicates the designated column's normal maximum width in characters.
*
* @param column the first column is 1, the second is 2, ...
* @return the normal maximum number of characters allowed as the width of the designated column
* @throws SQLException if a database access error occurs
*/
public int getColumnDisplaySize(final int column) throws SQLException {
return getColumnInformation(column).getDisplaySize();
}
/**
* Gets the designated column's suggested title for use in printouts and displays. The suggested
* title is usually specified by the SQL AS clause. If a SQL AS is not
* specified, the value returned from getColumnLabel will be the same as the value
* returned by the getColumnName method.
*
* @param column the first column is 1, the second is 2, ...
* @return the suggested column title
* @throws SQLException if a database access error occurs
*/
public String getColumnLabel(final int column) throws SQLException {
return getColumnInformation(column).getName();
}
/**
* Get the designated column's name.
*
* @param column the first column is 1, the second is 2, ...
* @return column name
* @throws SQLException if a database access error occurs
*/
public String getColumnName(final int column) throws SQLException {
String columnName = getColumnInformation(column).getOriginalName();
if ("".equals(columnName) || options.useOldAliasMetadataBehavior || forceAlias) {
return getColumnLabel(column);
}
return columnName;
}
/**
* Get the designated column's table's schema.
*
* @param column the first column is 1, the second is 2, ...
* @return schema name or "" if not applicable
* @throws SQLException if a database access error occurs
*/
public String getCatalogName(int column) throws SQLException {
return getColumnInformation(column).getDatabase();
}
/**
* Get the designated column's specified column size. 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 column the first column is 1, the second is 2, ...
* @return precision
* @throws SQLException if a database access error occurs
*/
public int getPrecision(final int column) throws SQLException {
return (int) getColumnInformation(column).getPrecision();
}
/**
* Gets the designated column's number of digits to right of the decimal point. 0 is returned for
* data types where the scale is not applicable.
*
* @param column the first column is 1, the second is 2, ...
* @return scale
* @throws SQLException if a database access error occurs
*/
public int getScale(final int column) throws SQLException {
return getColumnInformation(column).getDecimals();
}
/**
* Gets the designated column's table name.
*
* @param column the first column is 1, the second is 2, ...
* @return table name or "" if not applicable
* @throws SQLException if a database access error occurs
*/
public String getTableName(final int column) throws SQLException {
if (forceAlias) {
return getColumnInformation(column).getTable();
}
if (options.blankTableNameMeta) {
return "";
}
if (options.useOldAliasMetadataBehavior) {
return getColumnInformation(column).getTable();
}
return getColumnInformation(column).getOriginalTable();
}
public String getSchemaName(int column) {
return "";
}
/**
* Retrieves the designated column's SQL type.
*
* @param column the first column is 1, the second is 2, ...
* @return SQL type from java.sql.Types
* @throws SQLException if a database access error occurs
* @see Types
*/
public int getColumnType(final int column) throws SQLException {
ColumnDefinition ci = getColumnInformation(column);
switch (ci.getColumnType()) {
case BIT:
if (ci.getLength() == 1) {
return Types.BIT;
}
return Types.VARBINARY;
case TINYINT:
if (ci.getLength() == 1 && options.tinyInt1isBit) {
return Types.BIT;
}
return Types.TINYINT;
case YEAR:
if (options.yearIsDateType) {
return Types.DATE;
}
return Types.SMALLINT;
case BLOB:
if (ci.getLength() < 0 || ci.getLength() > 16777215) {
return Types.LONGVARBINARY;
}
return Types.VARBINARY;
case VARCHAR:
case VARSTRING:
if (ci.isBinary()) {
return Types.VARBINARY;
}
if (ci.getLength() < 0) {
return Types.LONGVARCHAR;
}
return Types.VARCHAR;
case STRING:
if (ci.isBinary()) {
return Types.BINARY;
}
return Types.CHAR;
default:
return ci.getColumnType().getSqlType();
}
}
/**
* Retrieves the designated column's database-specific type name.
*
* @param column the first column is 1, the second is 2, ...
* @return type name used by the database. If the column type is a user-defined type, then a
* fully-qualified type name is returned.
* @throws SQLException if a database access error occurs
*/
public String getColumnTypeName(final int column) throws SQLException {
ColumnDefinition ci = getColumnInformation(column);
return ColumnType.getColumnTypeName(
ci.getColumnType(), ci.getLength(), ci.getDisplaySize(), ci.isSigned(), ci.isBinary());
}
/**
* Indicates whether the designated column is definitely not writable.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs or in case of wrong index
*/
public boolean isReadOnly(final int column) throws SQLException {
ColumnDefinition ci = getColumnInformation(column);
return (ci.getOriginalTable() == null || ci.getOriginalTable().isEmpty())
&& (ci.getOriginalName() == null || ci.getOriginalName().isEmpty());
}
/**
* Indicates whether it is possible for a write on the designated column to succeed.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs or in case of wrong index
*/
public boolean isWritable(final int column) throws SQLException {
return !isReadOnly(column);
}
/**
* Indicates whether a write on the designated column will definitely succeed.
*
* @param column the first column is 1, the second is 2, ...
* @return true if so; false otherwise
* @throws SQLException if a database access error occurs or in case of wrong index
*/
public boolean isDefinitelyWritable(final int column) throws SQLException {
return !isReadOnly(column);
}
/**
* Returns the fully-qualified name of the Java class whose instances are manufactured if the
* method ResultSet.getObject is called to retrieve a value from the column.
* ResultSet.getObject may return a subclass of the class returned by this method.
*
* @param column the first column 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 ResultSet.getObject to retrieve the value in the specified
* column. This is the class name used for custom mapping.
* @throws SQLException if a database access error occurs
*/
public String getColumnClassName(int column) throws SQLException {
ColumnDefinition ci = getColumnInformation(column);
ColumnType type = ci.getColumnType();
return ColumnType.getClassName(
type, (int) ci.getLength(), ci.isSigned(), ci.isBinary(), options);
}
private ColumnDefinition getColumnInformation(int column) throws SQLException {
if (column >= 1 && column <= fieldPackets.length) {
return fieldPackets[column - 1];
}
throw ExceptionFactory.INSTANCE.create(
String.format(
"wrong column index %s. must be in [1, %s] range", column, fieldPackets.length));
}
/**
* 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.
*
* @param iface A Class defining an interface that the result must implement.
* @return 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
*/
public T unwrap(final Class iface) throws SQLException {
try {
if (isWrapperFor(iface)) {
return iface.cast(this);
} else {
throw new SQLException("The receiver is not a wrapper for " + iface.getName());
}
} catch (Exception e) {
throw new SQLException("The receiver is not a wrapper and does not implement the interface");
}
}
/**
* 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.
* @throws SQLException if an error occurs while determining whether this is a wrapper for an
* object with the given interface.
*/
public boolean isWrapperFor(final Class iface) throws SQLException {
return iface.isInstance(this);
}
}