db2 sql parser support concat binary operator

src/main/java/com/alibaba/druid/sql/dialect/db2/parser/DB2Lexer.java

@@ -37,6 +37,7 @@ public class DB2Lexer extends Lexer {
         map.put("ONLY", Token.ONLY);
         map.put("OPTIMIZE", Token.OPTIMIZE);
         map.put("OF", Token.OF);
+        map.put("CONCAT", Token.CONCAT);
         
         DEFAULT_DB2_KEYWORDS = new Keywords(map);
     }

src/main/java/com/alibaba/druid/sql/dialect/db2/visitor/DB2OutputVisitor.java

@@ -17,6 +17,7 @@ package com.alibaba.druid.sql.dialect.db2.visitor;
 
 import com.alibaba.druid.sql.ast.SQLObject;
 import com.alibaba.druid.sql.ast.SQLOrderBy;
+import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
 import com.alibaba.druid.sql.ast.statement.SQLSelect;
 import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
@@ -91,4 +92,12 @@ public class DB2OutputVisitor extends SQLASTOutputVisitor implements DB2ASTVisit
     public void endVisit(DB2ValuesStatement x) {
 
     }
+    
+    protected void printOperator(SQLBinaryOperator operator) {
+        if (operator == SQLBinaryOperator.Concat) {
+            print0(ucase ? "CONCAT" : "concat");
+        } else {
+            print0(ucase ? operator.name : operator.name_lcase);
+        }
+    }
 }

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

@@ -1223,7 +1223,7 @@ public class SQLExprParser extends SQLParser {
 
             expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.Add, rightExp, getDbType());
             expr = additiveRest(expr);
-        } else if (lexer.token() == Token.BARBAR) {
+        } else if (lexer.token() == Token.BARBAR || lexer.token() == Token.CONCAT) {
             lexer.nextToken();
             SQLExpr rightExp = multiplicative();
             expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.Concat, rightExp, getDbType());

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

@@ -277,6 +277,8 @@ public enum Token {
     FORMAT("FORMAT"),
     QUALIFY("QUALIFY"),
     MOD("MOD"),
+    
+    CONCAT("CONCAT"), // DB2
 
     LPAREN("("), 
     RPAREN(")"), 

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

@@ -329,7 +329,7 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Printab
             } else {
                 print0(" ");
             }
-            print0(ucase ? x.getOperator().name : x.getOperator().name_lcase);
+            printOperator(x.getOperator());
             print0(" ");
         }
 
@@ -342,6 +342,10 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Printab
         return false;
     }
 
+    protected void printOperator(SQLBinaryOperator operator) {
+        print0(ucase ? operator.name : operator.name_lcase);
+    }
+
     private void visitorBinaryRight(SQLBinaryOpExpr x) {
         if (isPrettyFormat() && x.getRight().hasBeforeComment()) {
             printlnComments(x.getRight().getBeforeCommentsDirect());

src/test/java/com/alibaba/druid/bvt/sql/db2/DB2SelectTest_11.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 1999-2101 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.bvt.sql.db2;
+
+import java.util.List;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.DB2Test;
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.db2.parser.DB2StatementParser;
+import com.alibaba.druid.sql.dialect.db2.visitor.DB2SchemaStatVisitor;
+import com.alibaba.druid.stat.TableStat;
+import com.alibaba.druid.stat.TableStat.Column;
+import com.alibaba.druid.util.JdbcConstants;
+
+public class DB2SelectTest_11 extends DB2Test {
+
+    public void test_0() throws Exception {
+        String sql = "SELECT A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nFROM A, B"
+                + "\nWHERE B.F_2211 = '5'"
+                + "\n    AND A.F_0301 = B.F_0301"
+                + "    AND Substr(B.F_0815, 1, 4) concat  Substr ( B.F_0815,5,2 ) > A.F_0802"
+                + "    AND A.F_2100 > 0"
+                + "\nUNION"
+                + "\nSELECT A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nFROM A"
+                + "\nWHERE A.F_0301 NOT IN (SELECT F_0301"
+                + "\n        FROM B)"
+                + "\n    AND A.F_2100 > 0";
+
+        DB2StatementParser parser = new DB2StatementParser(sql);
+        List<SQLStatement> statementList = parser.parseStatementList();
+        SQLStatement stmt = statementList.get(0);
+        print(statementList);
+
+        Assert.assertEquals(1, statementList.size());
+
+        DB2SchemaStatVisitor visitor = new DB2SchemaStatVisitor();
+        stmt.accept(visitor);
+
+//        System.out.println("Tables : " + visitor.getTables());
+//        System.out.println("fields : " + visitor.getColumns());
+//        System.out.println("coditions : " + visitor.getConditions());
+//        System.out.println("orderBy : " + visitor.getOrderByColumns());
+
+        Assert.assertEquals(2, visitor.getTables().size());
+        Assert.assertEquals(7, visitor.getColumns().size());
+        Assert.assertEquals(6, visitor.getConditions().size());
+
+        Assert.assertTrue(visitor.getTables().containsKey(new TableStat.Name("A")));
+
+         Assert.assertTrue(visitor.getColumns().contains(new Column("A", "F_0201")));
+        // Assert.assertTrue(visitor.getColumns().contains(new Column("mytable", "first_name")));
+        // Assert.assertTrue(visitor.getColumns().contains(new Column("mytable", "full_name")));
+
+        Assert.assertEquals("SELECT A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nFROM A, B"
+                + "\nWHERE B.F_2211 = '5'"
+                + "\n\tAND A.F_0301 = B.F_0301"
+                + "\n\tAND (Substr(B.F_0815, 1, 4) CONCAT Substr(B.F_0815, 5, 2)) > A.F_0802"
+                + "\n\tAND A.F_2100 > 0"
+                + "\nUNION"
+                + "\nSELECT A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nFROM A"
+                + "\nWHERE A.F_0301 NOT IN (SELECT F_0301"
+                + "\n\t\tFROM B)"
+                + "\n\tAND A.F_2100 > 0", //
+                            SQLUtils.toSQLString(stmt, JdbcConstants.DB2));
+        
+        Assert.assertEquals("select A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nfrom A, B"
+                + "\nwhere B.F_2211 = '5'"
+                + "\n\tand A.F_0301 = B.F_0301"
+                + "\n\tand (Substr(B.F_0815, 1, 4) concat Substr(B.F_0815, 5, 2)) > A.F_0802"
+                + "\n\tand A.F_2100 > 0"
+                + "\nunion"
+                + "\nselect A.F_0201, A.F_0301, A.F_0802, A.F_2100"
+                + "\nfrom A"
+                + "\nwhere A.F_0301 not in (select F_0301"
+                + "\n\t\tfrom B)"
+                + "\n\tand A.F_2100 > 0", //
+                            SQLUtils.toSQLString(stmt, JdbcConstants.DB2, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION));
+    }
+}