org.restsql.core.impl.mysql.MySqlSqlResourceMetaData.java Source code

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Here is the source code for org.restsql.core.impl.mysql.MySqlSqlResourceMetaData.java

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/* Copyright (c) restSQL Project Contributors. Licensed under MIT. */
package org.restsql.core.impl.mysql;

import java.sql.SQLException;

import org.restsql.core.impl.AbstractSqlResourceMetaData;
import org.restsql.core.impl.ColumnMetaDataImpl;
import org.restsql.core.sqlresource.SqlResourceDefinition;
import org.springframework.jdbc.support.rowset.SqlRowSet;
import org.springframework.jdbc.support.rowset.SqlRowSetMetaData;

/**
 * Implements SqlResourceMetaData for MySQL.
 * 
 * @author Mark Sawers
 */
public class MySqlSqlResourceMetaData extends AbstractSqlResourceMetaData {
    private static final String SQL_COLUMNS_QUERY = "select column_name, data_type, extra from information_schema.columns where table_schema = ? and table_name = ?";
    private static final String SQL_PK_QUERY = "select column_name from information_schema.table_constraints tc, information_schema.key_column_usage kcu"
            + " where tc.constraint_schema= ? and tc.table_name = ?" + " and tc.constraint_type = 'PRIMARY KEY'"
            + " and tc.constraint_schema = kcu.constraint_schema and tc.table_name = kcu.table_name"
            + " and tc.constraint_name = kcu.constraint_name";

    /**
     * Retrieves sql for querying columns. Hook method for
     * buildInvisibleForeignKeys() and buildJoinTableMetadata() allows
     * database-specific overrides.
     */
    @Override
    protected String getSqlColumnsQuery() {
        return SQL_COLUMNS_QUERY;
    }

    /**
     * Retrieves sql for querying primary keys. Hook method for buildPrimaryKeys
     * allows database-specific overrides.
     */
    @Override
    protected String getSqlPkQuery() {
        return SQL_PK_QUERY;
    }

    /** Retrieves database-specific table name used in SQL statements. */
    @Override
    protected String getQualifiedTableName(final SqlResourceDefinition definition,
            final SqlRowSetMetaData resultSetMetaData, final int colNumber) {
        return resultSetMetaData.getCatalogName(colNumber) + "." + resultSetMetaData.getTableName(colNumber);
    }

    /**
     * Retrieves database-specific table name used in SQL statements. Used to
     * build join table meta data.
     */
    @Override
    protected String getQualifiedTableName(String databaseName, String tableName) {
        return databaseName + "." + tableName;
    }

    /**
     * Sets sequence metadata for a column with the columns query result set.
     * The extra column value will contain the string auto_increment if this is
     * a sequence.
     * 
     * @throws SQLException
     *             when a database error occurs
     */
    @Override
    protected void setSequenceMetaData(ColumnMetaDataImpl column, SqlRowSet resultSet) {
        final String extra = resultSet.getString(3);
        if (extra != null && extra.equals("auto_increment")) {
            column.setSequence(true);
            column.setSequenceName(column.getTableName());
        }
    }
}