优化MySQL8.x的json类型字段默认值解析逻辑 #6102

优化MySQL8.x的json类型字段默认值解析逻辑 #6102

Author: lizongbo

core/src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/expr/MySqlCharExpr.java

@@ -24,7 +24,7 @@ public class MySqlCharExpr extends SQLCharExpr implements MySqlExpr {
     private String collate;
 
     private String type;
-
+    protected boolean parenthesized;
     public MySqlCharExpr() {
     }
 
@@ -67,6 +67,16 @@ public void setType(String type) {
         this.type = type;
     }
 
+    @Override
+    public boolean isParenthesized() {
+        return parenthesized;
+    }
+
+    @Override
+    public void setParenthesized(boolean parenthesized) {
+        this.parenthesized = parenthesized;
+    }
+
     public void output(StringBuilder buf) {
         if (charset != null) {
             buf.append(charset);

core/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlExprParser.java

@@ -1048,8 +1048,8 @@ public SQLExpr primary() {
                                 accept(Token.IDENTIFIER);
                             }
                         }
-
-                        charExpr = new MySqlCharExpr(str, "_utf8", collate);
+                        String charset = hash_lower == FnvHash.Constants._UTF8 ? "_utf8" : "_utf8mb4";
+                        charExpr = new MySqlCharExpr(str, charset, collate);
                     } else {
                         String str = MySqlUtils.utf8(hexString);
                         charExpr = new SQLCharExpr(str);

core/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -3767,7 +3767,9 @@ public boolean visit(MySqlCharExpr x) {
             }
             return false;
         }
-
+        if (x.isParenthesized()) {
+            print("(");
+        }
         String charset = x.getCharset();
         String collate = x.getCollate();
         String text = x.getText();
@@ -3793,6 +3795,9 @@ public boolean visit(MySqlCharExpr x) {
             print(" COLLATE ");
             print(collate);
         }
+        if (x.isParenthesized()) {
+            print(")");
+        }
         return false;
     }
 

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

@@ -20,6 +20,7 @@
 import com.alibaba.druid.sql.ast.*;
 import com.alibaba.druid.sql.ast.expr.*;
 import com.alibaba.druid.sql.ast.statement.*;
+import com.alibaba.druid.sql.dialect.mysql.ast.expr.MySqlCharExpr;
 import com.alibaba.druid.sql.dialect.oracle.ast.expr.OracleArgumentExpr;
 import com.alibaba.druid.sql.parser.Lexer.SavePoint;
 import com.alibaba.druid.util.FnvHash;
@@ -157,6 +158,9 @@ public SQLExpr expr() {
             if (parenthesized && sqlExpr instanceof SQLUnaryExpr) {
                 ((SQLUnaryExpr) sqlExpr).setParenthesized(true);
             }
+            if (parenthesized && sqlExpr instanceof MySqlCharExpr) {
+                ((MySqlCharExpr) sqlExpr).setParenthesized(true);
+            }
             return sqlExpr;
         }
     }

core/src/test/java/com/alibaba/druid/bvt/sql/mysql/issues/Issue6102.java

@@ -0,0 +1,51 @@
+package com.alibaba.druid.bvt.sql.mysql.issues;
+
+import java.util.List;
+
+import com.alibaba.druid.DbType;
+import com.alibaba.druid.sql.SQLParseAssertUtil;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.parser.SQLParserUtils;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author lizongbo
+ * @see <a href="https://github.com/alibaba/druid/issues/6102" >Issue来源</a>
+ * @see <a href="https://dev.mysql.com/doc/refman/8.4/en/create-table.html">mysql create table </a>
+ */
+public class Issue6102 {
+
+
+    @Test
+    public void test_parse_create() {
+        for (DbType dbType : new DbType[]{DbType.mysql}) {
+            for (String sql : new String[]{
+                "CREATE TABLE `account_info` (\n"
+                    + "  `id` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '主键id',\n"
+                    + "  `account_num` varchar(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL COMMENT '账户编号',\n"
+                    + "  `open_acct_agreement_info` json DEFAULT (_utf8mb4'{}') COMMENT '协议信息',\n"
+                    + "  `ext_info` json DEFAULT (_utf8mb4'{}') COMMENT '扩展信息',\n"
+                    + "  `last_push_time` datetime DEFAULT NULL COMMENT '账户推送时间',\n"
+                    + "  `create_time` datetime NOT NULL COMMENT '创建时间',\n"
+                    + "  `update_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '最后更新时间',\n"
+                    + "  PRIMARY KEY (`id`) USING BTREE,\n"
+                    + "  UNIQUE KEY `idx_account_num` (`account_num`) USING BTREE\n"
+                    + ") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin ROW_FORMAT=COMPACT COMMENT='账户信息表';",
+
+            }) {
+                SQLStatementParser parser = SQLParserUtils.createSQLStatementParser(sql, dbType);
+                List<SQLStatement> statementList = parser.parseStatementList();
+                System.out.println(statementList);
+                String sqlnew=statementList.toString();
+                assertTrue(sqlnew.contains("DEFAULT (_utf8mb4 '{}')"));
+                SQLParseAssertUtil.assertParseSql(sql, dbType);
+            }
+        }
+    }
+
+
+}