/**
* Create the compatible Query object based on the SQL query.
*
* @param sql The SQL query.
* @return Query object.
*/
public static QueryAction create(Client client, String sql)
throws SqlParseException, SQLFeatureNotSupportedException {
sql = sql.replaceAll("\n", " ");
String firstWord = sql.substring(0, sql.indexOf(' '));
switch (firstWord.toUpperCase()) {
case "SELECT":
SQLQueryExpr sqlExpr = (SQLQueryExpr) toSqlExpr(sql);
if (isMulti(sqlExpr)) {
MultiQuerySelect multiSelect =
new SqlParser().parseMultiSelect((SQLUnionQuery) sqlExpr.getSubQuery().getQuery());
handleSubQueries(client, multiSelect.getFirstSelect());
handleSubQueries(client, multiSelect.getSecondSelect());
return new MultiQueryAction(client, multiSelect);
} else if (isJoin(sqlExpr, sql)) {
JoinSelect joinSelect = new SqlParser().parseJoinSelect(sqlExpr);
handleSubQueries(client, joinSelect.getFirstTable());
handleSubQueries(client, joinSelect.getSecondTable());
return ESJoinQueryActionFactory.createJoinAction(client, joinSelect);
} else {
Select select = new SqlParser().parseSelect(sqlExpr);
handleSubQueries(client, select);
return handleSelect(client, select);
}
case "DELETE":
SQLStatementParser parser = createSqlStatementParser(sql);
SQLDeleteStatement deleteStatement = parser.parseDeleteStatement();
Delete delete = new SqlParser().parseDelete(deleteStatement);
return new DeleteQueryAction(client, delete);
case "SHOW":
return new ShowQueryAction(client, sql);
default:
throw new SQLFeatureNotSupportedException(String.format("Unsupported query: %s", sql));
}
}
public static boolean visit(SQLEvalVisitor visitor, SQLQueryExpr x) {
if (x.getSubQuery().getQuery() instanceof SQLSelectQueryBlock) {
SQLSelectQueryBlock queryBlock = (SQLSelectQueryBlock) x.getSubQuery().getQuery();
boolean nullFrom = false;
if (queryBlock.getFrom() == null) {
nullFrom = true;
} else if (queryBlock.getFrom() instanceof SQLExprTableSource) {
SQLExpr expr = ((SQLExprTableSource) queryBlock.getFrom()).getExpr();
if (expr instanceof SQLIdentifierExpr) {
if ("dual".equalsIgnoreCase(((SQLIdentifierExpr) expr).getName())) {
nullFrom = true;
}
}
}
if (nullFrom) {
List<Object> row = new ArrayList<Object>(queryBlock.getSelectList().size());
for (int i = 0; i < queryBlock.getSelectList().size(); ++i) {
SQLSelectItem item = queryBlock.getSelectList().get(i);
item.getExpr().accept(visitor);
Object cell = item.getExpr().getAttribute(EVAL_VALUE);
row.add(cell);
}
List<List<Object>> rows = new ArrayList<List<Object>>(1);
rows.add(row);
Object result = rows;
queryBlock.putAttribute(EVAL_VALUE, result);
x.getSubQuery().putAttribute(EVAL_VALUE, result);
x.putAttribute(EVAL_VALUE, result);
return false;
}
}
return false;
}
private static boolean isMulti(SQLQueryExpr sqlExpr) {
return sqlExpr.getSubQuery().getQuery() instanceof SQLUnionQuery;
}
private static boolean isJoin(SQLQueryExpr sqlExpr, String sql) {
MySqlSelectQueryBlock query = (MySqlSelectQueryBlock) sqlExpr.getSubQuery().getQuery();
return query.getFrom() instanceof SQLJoinTableSource && sql.toLowerCase().contains("join");
}