improve sql parser

src/main/java/com/alibaba/druid/sql/ast/statement/SQLCheck.java

@@ -23,12 +23,23 @@ public class SQLCheck extends SQLConstaintImpl implements SQLTableElement {
     private static final long serialVersionUID = 1L;
 
     private SQLExpr           expr;
+    
+    public SQLCheck() {
+        
+    }
+    
+    public SQLCheck(SQLExpr expr) {
+        this.setExpr(expr);
+    }
 
     public SQLExpr getExpr() {
         return expr;
     }
 
     public void setExpr(SQLExpr expr) {
+        if (expr != null) {
+            expr.setParent(this);
+        }
         this.expr = expr;
     }
 

src/main/java/com/alibaba/druid/sql/ast/statement/SQLColumnCheck.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.sql.ast.statement;
+
+import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+public class SQLColumnCheck extends SQLConstaintImpl implements SQLColumnConstraint {
+
+    private static final long serialVersionUID = 1L;
+    
+    private SQLExpr expr;
+   
+    public SQLColumnCheck() {
+        
+    }
+    
+    public SQLColumnCheck(SQLExpr expr) {
+        this.setExpr(expr);
+    }
+    
+    public SQLExpr getExpr() {
+        return expr;
+    }
+    
+    public void setExpr(SQLExpr expr) {
+        if (expr != null) {
+            expr.setParent(this);
+        }
+        this.expr = expr;
+    }
+
+
+    @Override
+    protected void accept0(SQLASTVisitor visitor) {
+        if (visitor.visit(this)) {
+            acceptChild(visitor, this.getName());
+            acceptChild(visitor, this.getExpr());
+        }
+        visitor.endVisit(this);
+    }
+
+}

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

@@ -61,6 +61,7 @@ import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
 import com.alibaba.druid.sql.ast.statement.NotNullConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLAssignItem;
 import com.alibaba.druid.sql.ast.statement.SQLCharactorDataType;
+import com.alibaba.druid.sql.ast.statement.SQLColumnCheck;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLColumnPrimaryKey;
 import com.alibaba.druid.sql.ast.statement.SQLPrimaryKey;
@@ -1255,6 +1256,13 @@ public class SQLExprParser extends SQLParser {
             column.getConstaints().add(new SQLColumnPrimaryKey());
             return parseColumnRest(column);
         }
+        
+        if (lexer.token == Token.CHECK) {
+            lexer.nextToken();
+            SQLExpr expr = this.expr();
+            column.getConstaints().add(new SQLColumnCheck(expr));
+            return parseColumnRest(column);
+        }
 
         return column;
     }

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

@@ -83,6 +83,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAssignItem;
 import com.alibaba.druid.sql.ast.statement.SQLCallStatement;
 import com.alibaba.druid.sql.ast.statement.SQLCharactorDataType;
 import com.alibaba.druid.sql.ast.statement.SQLCheck;
+import com.alibaba.druid.sql.ast.statement.SQLColumnCheck;
 import com.alibaba.druid.sql.ast.statement.SQLColumnConstraint;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLColumnPrimaryKey;
@@ -1333,6 +1334,13 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter {
         print(" PRIMARY KEY");
         return false;
     }
+    
+    @Override
+    public boolean visit(SQLColumnCheck x) {
+        print("CHECK ");
+        x.getExpr().accept(this);
+        return false;
+    }
 
     @Override
     public boolean visit(SQLColumnUniqueIndex x) {

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

@@ -70,6 +70,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAssignItem;
 import com.alibaba.druid.sql.ast.statement.SQLCallStatement;
 import com.alibaba.druid.sql.ast.statement.SQLCharactorDataType;
 import com.alibaba.druid.sql.ast.statement.SQLCheck;
+import com.alibaba.druid.sql.ast.statement.SQLColumnCheck;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLColumnPrimaryKey;
 import com.alibaba.druid.sql.ast.statement.SQLColumnUniqueIndex;
@@ -469,4 +470,8 @@ public interface SQLASTVisitor {
     boolean visit(SQLAlterTableEnableConstraint x);
     
     void endVisit(SQLAlterTableEnableConstraint x);
+
+    boolean visit(SQLColumnCheck x);
+    
+    void endVisit(SQLColumnCheck x);
 }

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

@@ -70,6 +70,7 @@ import com.alibaba.druid.sql.ast.statement.SQLAssignItem;
 import com.alibaba.druid.sql.ast.statement.SQLCallStatement;
 import com.alibaba.druid.sql.ast.statement.SQLCharactorDataType;
 import com.alibaba.druid.sql.ast.statement.SQLCheck;
+import com.alibaba.druid.sql.ast.statement.SQLColumnCheck;
 import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
 import com.alibaba.druid.sql.ast.statement.SQLColumnPrimaryKey;
 import com.alibaba.druid.sql.ast.statement.SQLColumnUniqueIndex;
@@ -874,5 +875,14 @@ public class SQLASTVisitorAdapter implements SQLASTVisitor {
     @Override
     public void endVisit(SQLAlterTableEnableConstraint x) {
         
+    }
+    @Override
+    public boolean visit(SQLColumnCheck x) {
+        return true;
+    }
+    
+    @Override
+    public void endVisit(SQLColumnCheck x) {
+        
     }
 }