de.akquinet.jbosscc.guttenbase.statements.AbstractSelectStatementCreator Maven / Gradle / Ivy

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package de.akquinet.jbosscc.guttenbase.statements;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.List;

import de.akquinet.jbosscc.guttenbase.hints.ColumnOrderHint;
import de.akquinet.jbosscc.guttenbase.meta.ColumnMetaData;
import de.akquinet.jbosscc.guttenbase.meta.TableMetaData;
import de.akquinet.jbosscc.guttenbase.repository.ConnectorRepository;
import de.akquinet.jbosscc.guttenbase.tools.CheckEqualTableDataTool;

/**
 * Create SELECT statement for copying data.
 * 
 * 
 * © 2012 akquinet tech@spree
 * 
 * 
 * @author M. Dahm
 */
public abstract class AbstractSelectStatementCreator extends AbstractStatementCreator {
	public static final String FROM = " FROM ";

	public AbstractSelectStatementCreator(final ConnectorRepository connectorRepository, final String connectorId) {
		super(connectorRepository, connectorId);
	}

	/**
	 * Create SELECT statement in the spource table to retrieve data from the configured source columns.
	 */
	public PreparedStatement createSelectStatement(final String tableName, final TableMetaData tableMetaData, final Connection connection)
			throws SQLException {
		final List columns = ColumnOrderHint.getSortedColumns(_connectorRepository, _connectorId, tableMetaData);
		final String sql = createSQL(tableName, tableMetaData, columns);
		LOG.debug("Create SELECT statement " + sql);

		return connection.prepareStatement(sql);
	}

	/**
	 * Create SELECT statement in the target table to retrieve data from the mapped columns. I.e., since the target table configuration may be
	 * different, the SELECT statement may be different.
	 * 
	 * This is needed to check data compatibility with the {@link CheckEqualTableDataTool}
	 */
	public PreparedStatement createMappedSelectStatement(final TableMetaData sourceTableMetaData, final String tableName,
			final TableMetaData targetTableMetaData, final Connection connection, final String sourceConnectorId) throws SQLException {
		final List columns = getMappedTargetColumns(sourceTableMetaData, targetTableMetaData, sourceConnectorId);
		final String sql = createSQL(tableName, targetTableMetaData, columns);

		return connection.prepareStatement(sql);
	}

	/**
	 * Try to retrieve data in some deterministic order
	 */
	protected String createOrderBy(final TableMetaData tableMetaData) throws SQLException {
		return "";
	}

	private String createSQL(final String tableName, final TableMetaData tableMetaData, final List columns)
			throws SQLException {
		final StringBuilder buf = new StringBuilder("SELECT ");

		buf.append(createColumnClause(columns));
		buf.append(FROM + tableName);

		buf.append(" " + createWhereClause(tableMetaData));
		buf.append(" " + createOrderBy(tableMetaData));

		return buf.toString();
	}
}