Merge remote-tracking branch 'upstream/master'

src/main/java/com/alibaba/druid/sql/ast/expr/SQLBinaryOpExpr.java

@@ -41,8 +41,8 @@ public class SQLBinaryOpExpr extends SQLExprImpl implements Serializable {
 
     public SQLBinaryOpExpr(SQLExpr left, SQLExpr right, SQLBinaryOperator operator){
 
-        this.left = left;
-        this.right = right;
+        setLeft(left);
+        setRight(right);
         this.operator = operator;
     }
 

src/main/java/com/alibaba/druid/sql/ast/expr/SQLCaseExpr.java

@@ -63,6 +63,9 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
     }
 
     public void setValueExpr(SQLExpr valueExpr) {
+        if (valueExpr != null) {
+            valueExpr.setParent(this);
+        }
         this.valueExpr = valueExpr;
     }
 
@@ -71,6 +74,9 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
     }
 
     public void setElseExpr(SQLExpr elseExpr) {
+        if (elseExpr != null) {
+            elseExpr.setParent(this);
+        }
         this.elseExpr = elseExpr;
     }
 
@@ -78,6 +84,13 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
         return this.items;
     }
 
+    public void addItem(Item item) {
+        if (item != null) {
+            item.setParent(this);
+            this.items.add(item);
+        }
+    }
+
     protected void accept0(SQLASTVisitor visitor) {
         if (visitor.visit(this)) {
             acceptChild(visitor, this.valueExpr);
@@ -99,8 +112,8 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
 
         public Item(SQLExpr conditionExpr, SQLExpr valueExpr){
 
-            this.conditionExpr = conditionExpr;
-            this.valueExpr = valueExpr;
+            setConditionExpr(conditionExpr);
+            setValueExpr(valueExpr);
         }
 
         public SQLExpr getConditionExpr() {
@@ -108,6 +121,9 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
         }
 
         public void setConditionExpr(SQLExpr conditionExpr) {
+            if (conditionExpr != null) {
+                conditionExpr.setParent(this);
+            }
             this.conditionExpr = conditionExpr;
         }
 
@@ -116,6 +132,9 @@ public class SQLCaseExpr extends SQLExprImpl implements Serializable {
         }
 
         public void setValueExpr(SQLExpr valueExpr) {
+            if (valueExpr != null) {
+                valueExpr.setParent(this);
+            }
             this.valueExpr = valueExpr;
         }
 

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -241,7 +241,7 @@ public class SQLExprParser extends SQLParser {
                 accept(Token.THEN);
                 SQLExpr valueExpr = expr();
                 SQLCaseExpr.Item caseItem = new SQLCaseExpr.Item(testExpr, valueExpr);
-                caseExpr.getItems().add(caseItem);
+                caseExpr.addItem(caseItem);
 
                 while (lexer.token() == Token.WHEN) {
                     lexer.nextToken();

src/main/java/com/alibaba/druid/sql/visitor/SQLEvalVisitorUtils.java

@@ -797,6 +797,9 @@ public class SQLEvalVisitorUtils {
             wallConditionContext.setConstArithmetic(true);
         }
 
+        leftValue = processValue(leftValue);
+        rightValue = processValue(rightValue);
+
         if (leftValue == null || rightValue == null) {
             return false;
         }
@@ -890,6 +893,17 @@ public class SQLEvalVisitorUtils {
         return false;
     }
 
+    @SuppressWarnings("rawtypes")
+    private static Object processValue(Object value) {
+        if (value instanceof List) {
+            List list = (List) value;
+            if (list.size() == 1) {
+                return processValue(list.get(0));
+            }
+        }
+        return value;
+    }
+
     private static boolean isAlwayTrueLikePattern(SQLExpr x) {
         if (x instanceof SQLCharExpr) {
             String text = ((SQLCharExpr) x).getText();
@@ -1223,7 +1237,7 @@ public class SQLEvalVisitorUtils {
         }
 
         if (a instanceof String || b instanceof String) {
-            return ((String) a).compareTo((String) b) > 0;
+            return castToString(a).compareTo(castToString(b)) > 0;
         }
 
         if (a instanceof BigDecimal || b instanceof BigDecimal) {

src/main/java/com/alibaba/druid/sql/visitor/functions/Isnull.java

@@ -38,8 +38,10 @@ public class Isnull implements Function {
         SQLExpr condition = parameters.get(0);
         condition.accept(visitor);
         Object itemValue = condition.getAttributes().get(EVAL_VALUE);
-        if (itemValue == null || itemValue == EVAL_VALUE_NULL) {
+        if (itemValue == EVAL_VALUE_NULL) {
             return Boolean.TRUE;
+        } else if (itemValue == null) {
+            return null;
         } else {
             return Boolean.FALSE;
         }

src/main/java/com/alibaba/druid/sql/visitor/functions/Right.java

@@ -22,10 +22,10 @@ import com.alibaba.druid.sql.ast.expr.SQLMethodInvokeExpr;
 import com.alibaba.druid.sql.visitor.SQLEvalVisitor;
 import com.alibaba.druid.sql.visitor.SQLEvalVisitorUtils;
 
-
 public class Right implements Function {
+
     public final static Right instance = new Right();
-    
+
     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
         if (x.getParameters().size() != 2) {
             return SQLEvalVisitor.EVAL_ERROR;
@@ -45,7 +45,11 @@ public class Right implements Function {
         String strValue = param0Value.toString();
         int intValue = SQLEvalVisitorUtils.castToInteger(param1Value);
 
-        String result = strValue.substring(strValue.length() - intValue, strValue.length());
+        int start = strValue.length() - intValue;
+        if (start < 0) {
+            start = 0;
+        }
+        String result = strValue.substring(start, strValue.length());
         return result;
     }
 }