distinguish limit 0 in analyze (#186)

apache · Mar 12, 2018 · b8fa22d · b8fa22d
1 parent 12d54c7
commit b8fa22d
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/fe/src/com/baidu/palo/analysis/LimitElement.java b/fe/src/com/baidu/palo/analysis/LimitElement.java
@@ -91,7 +91,13 @@ public String toSql() {
         sb.append("" + limit);
         return sb.toString();
     }
+
+    public void analyze(Analyzer analyzer) {
+        if (limit == 0) analyzer.setHasEmptyResultSet();
+    }
 
     public void reset() {
+        limit = -1;
+        offset = 0;
     }
 }
diff --git a/fe/src/com/baidu/palo/analysis/QueryStmt.java b/fe/src/com/baidu/palo/analysis/QueryStmt.java
@@ -110,10 +110,19 @@ public abstract class QueryStmt extends StatementBase {
     public void analyze(Analyzer analyzer) throws AnalysisException, InternalException {
         if (isAnalyzed()) return;
         super.analyze(analyzer);
-        // analyzeLimit(analyzer);
+        analyzeLimit(analyzer);
         if (hasWithClause()) withClause_.analyze(analyzer);
     }
 
+    private void analyzeLimit(Analyzer analyzer) throws AnalysisException {
+        // TODO chenhao
+        if (limitElement.getOffset() > 0 && !hasOrderByClause()) {
+          throw new AnalysisException("OFFSET requires an ORDER BY clause: " +
+                  limitElement.toSql().trim());
+        }
+        limitElement.analyze(analyzer);
+    }
+
     /**
      * Returns a list containing all the materialized tuple ids that this stmt is
      * correlated with (i.e., those tuple ids from outer query blocks that TableRefs