@Override
public void rewriteContext(CubeQueryContext cubeql) throws LensException {
Map<String, String> colToTableAlias = cubeql.getColToTableAlias();
extractTabAliasForCol(cubeql);
findDimAttributesAndMeasures(cubeql);
if (colToTableAlias.isEmpty()) {
return;
}
// Rewrite the all the columns in the query with table alias prefixed.
// If col1 of table tab1 is accessed, it would be changed as tab1.col1.
// If tab1 is already aliased say with t1, col1 is changed as t1.col1
// replace the columns in select, groupby, having, orderby by
// prepending the table alias to the col
// sample select trees
// 1: (TOK_SELECT (TOK_SELEXPR (TOK_TABLE_OR_COL key))
// (TOK_SELEXPR (TOK_FUNCTION count (TOK_TABLE_OR_COL value))))
// 2: (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL src) key))
// (TOK_SELEXPR (TOK_FUNCTION count (. (TOK_TABLE_OR_COL src) value))))
// 3: (TOK_SELECT (TOK_SELEXPR (. (TOK_TABLE_OR_COL src) key) srckey))))
replaceAliases(cubeql.getSelectAST(), 0, colToTableAlias);
replaceAliases(cubeql.getHavingAST(), 0, colToTableAlias);
replaceAliases(cubeql.getOrderByAST(), 0, colToTableAlias);
replaceAliases(cubeql.getGroupByAST(), 0, colToTableAlias);
replaceAliases(cubeql.getWhereAST(), 0, colToTableAlias);
replaceAliases(cubeql.getJoinAST(), 0, colToTableAlias);
// Update the aggregate expression set
AggregateResolver.updateAggregates(cubeql.getSelectAST(), cubeql);
AggregateResolver.updateAggregates(cubeql.getHavingAST(), cubeql);
// Update alias map as well
updateAliasMap(cubeql.getSelectAST(), cubeql);
}
public void replaceAliasInAST(CubeQueryContext cubeql) throws SemanticException {
AliasReplacer.extractTabAliasForCol(cubeql, this);
AliasReplacer.replaceAliases(finalAST, 0, cubeql.getColToTableAlias());
}
private void extractTabAliasForCol(CubeQueryContext cubeql) throws LensException {
extractTabAliasForCol(cubeql, cubeql);
}