| // 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.client.result; |
| |
| import java.sql.SQLException; |
| import java.sql.Types; |
| import org.mariadb.jdbc.Configuration; |
| import org.mariadb.jdbc.client.Column; |
| import org.mariadb.jdbc.client.ColumnDecoder; |
| import org.mariadb.jdbc.export.ExceptionFactory; |
| import org.mariadb.jdbc.util.constants.ColumnFlags; |
| |
| /** Result-set metadata */ |
| public class ResultSetMetaData implements java.sql.ResultSetMetaData { |
| |
| private final ExceptionFactory exceptionFactory; |
| private final ColumnDecoder[] fieldPackets; |
| private final Configuration conf; |
| private final boolean forceAlias; |
| |
| /** |
| * Constructor. |
| * |
| * @param exceptionFactory default exception handler |
| * @param fieldPackets column informations |
| * @param conf connection options |
| * @param forceAlias force table and column name alias as original data |
| */ |
| public ResultSetMetaData( |
| final ExceptionFactory exceptionFactory, |
| final ColumnDecoder[] fieldPackets, |
| final Configuration conf, |
| final boolean forceAlias) { |
| this.exceptionFactory = exceptionFactory; |
| this.fieldPackets = fieldPackets; |
| this.conf = conf; |
| this.forceAlias = forceAlias; |
| } |
| |
| /** |
| * Returns the number of columns in this <code>ResultSet</code> 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 <code>true</code> if so; <code>false</code> otherwise |
| * @throws SQLException if a database access error occurs |
| */ |
| public boolean isAutoIncrement(final int column) throws SQLException { |
| return (getColumn(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 <code>true</code> if so; <code>false</code> otherwise |
| */ |
| public boolean isCaseSensitive(final int column) { |
| return true; |
| } |
| |
| /** |
| * Indicates whether the designated column can be used in a where clause. |
| * |
| * @param column the first column is 1, the second is 2, ... |
| * @return <code>true</code> if so; <code>false</code> 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 <code>true</code> if so; <code>false</code> 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 <code>columnNoNulls</code>, <code> |
| * columnNullable</code> or <code>columnNullableUnknown</code> |
| * @throws SQLException if a database access error occurs |
| */ |
| public int isNullable(final int column) throws SQLException { |
| if ((getColumn(column).getFlags() & ColumnFlags.NOT_NULL) == 0) { |
| return java.sql.ResultSetMetaData.columnNullable; |
| } else { |
| return java.sql.ResultSetMetaData.columnNoNulls; |
| } |
| } |
| |
| /** |
| * Indicates whether values in the designated column are signed numbers. |
| * |
| * @param column the first column is 1, the second is 2, ... |
| * @return <code>true</code> if so; <code>false</code> otherwise |
| * @throws SQLException if a database access error occurs |
| */ |
| public boolean isSigned(int column) throws SQLException { |
| return getColumn(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 getColumn(column).getDisplaySize(); |
| } |
| |
| /** |
| * Gets the designated column's suggested title for use in printouts and displays. The suggested |
| * title is usually specified by the SQL <code>AS</code> clause. If an SQL <code>AS</code> is not |
| * specified, the value returned from <code>getColumnLabel</code> will be the same as the value |
| * returned by the <code>getColumnName</code> 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 getColumn(column).getColumnAlias(); |
| } |
| |
| /** |
| * Get the designated column's name. |
| * |
| * @param idx 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 idx) throws SQLException { |
| Column column = getColumn(idx); |
| String columnName = column.getColumnName(); |
| if ("".equals(columnName) || forceAlias) { |
| return column.getColumnAlias(); |
| } |
| 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 getColumn(column).getSchema(); |
| } |
| |
| /** |
| * 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 getColumn(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 index the first column is 1, the second is 2, ... |
| * @return scale |
| * @throws SQLException if a database access error occurs |
| */ |
| public int getScale(final int index) throws SQLException { |
| return getColumn(index).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 getColumn(column).getTableAlias(); |
| } |
| |
| if (conf.blankTableNameMeta()) { |
| return ""; |
| } |
| |
| return getColumn(column).getTable(); |
| } |
| |
| 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 { |
| return getColumn(column).getColumnType(conf); |
| } |
| |
| /** |
| * Retrieves the designated column's database-specific type name. |
| * |
| * @param index 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 index) throws SQLException { |
| return getColumn(index).getColumnTypeName(conf); |
| } |
| |
| /** |
| * Indicates whether the designated column is definitely not writable. |
| * |
| * @param column the first column is 1, the second is 2, ... |
| * @return <code>true</code> if so; <code>false</code> otherwise |
| * @throws SQLException if a database access error occurs or in case of wrong index |
| */ |
| public boolean isReadOnly(final int column) throws SQLException { |
| Column ci = getColumn(column); |
| return ci.getColumnName().isEmpty(); |
| } |
| |
| /** |
| * Indicates whether it is possible for writing on the designated column to succeed. |
| * |
| * @param column the first column is 1, the second is 2, ... |
| * @return <code>true</code> if so; <code>false</code> 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 writing on the designated column will definitely succeed. |
| * |
| * @param column the first column is 1, the second is 2, ... |
| * @return <code>true</code> if so; <code>false</code> 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 <code>ResultSet.getObject</code> is called to retrieve a value from the column. <code> |
| * ResultSet.getObject</code> 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 <code>ResultSet.getObject</code> 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 { |
| return getColumn(column).defaultClassname(conf); |
| } |
| |
| private ColumnDecoder getColumn(int column) throws SQLException { |
| if (column >= 1 && column <= fieldPackets.length) { |
| return fieldPackets[column - 1]; |
| } |
| throw exceptionFactory.create(String.format("wrong column index %s", column)); |
| } |
| |
| /** |
| * Returns an object that implements the given interface to allow access to non-standard methods, |
| * or standard methods not exposed by the proxy. <br> |
| * 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 <code>unwrap</code> 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 <code>SQLException |
| * </code> 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 |
| */ |
| public <T> T unwrap(final Class<T> 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 <code> |
| * isWrapperFor</code> 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 |
| * <code>unwrap</code> so that callers can use this method to avoid expensive <code>unwrap</code> |
| * calls that may fail. If this method returns true then calling <code>unwrap</code> 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. |
| */ |
| public boolean isWrapperFor(final Class<?> iface) { |
| return iface.isInstance(this); |
| } |
| } |