优化 drop column if exists的解析支持 alibaba#5797

lizongbo · Mar 24, 2024 · 3dd61cd · 3dd61cd
1 parent 1a9f216
commit 3dd61cd
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Showing 4 changed files with 77 additions and 2 deletions.
diff --git a/core/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java b/core/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java
@@ -8002,7 +8002,11 @@ public void parseAlterDrop(SQLAlterTableStatement stmt) {
         } else if (lexer.token() == Token.COLUMN) {
             lexer.nextToken();
             SQLAlterTableDropColumnItem item = new SQLAlterTableDropColumnItem();
-
+            if (lexer.token() == Token.IF) {
+                lexer.nextToken();
+                accept(Token.EXISTS);
+                item.setIfExists(true);
+            }
             SQLName name = exprParser.name();
             name.setParent(item);
             item.addColumn(name);

diff --git a/core/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleStatementParser.java b/core/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleStatementParser.java
@@ -1746,6 +1746,11 @@ public void parseAlterDrop(SQLAlterTableStatement stmt) {
         } else if (lexer.token() == Token.COLUMN) {
             lexer.nextToken();
             SQLAlterTableDropColumnItem item = new SQLAlterTableDropColumnItem();
+            if (lexer.token() == Token.IF) {
+                lexer.nextToken();
+                accept(Token.EXISTS);
+                item.setIfExists(true);
+            }
             this.exprParser.names(item.getColumns());
             stmt.addItem(item);
         } else if (lexer.token() == Token.PARTITION) {

diff --git a/...rc/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerStatementParser.java b/...rc/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerStatementParser.java
@@ -590,7 +590,11 @@ public void parseAlterDrop(SQLAlterTableStatement stmt) {
         } else if (lexer.token() == Token.COLUMN) {
             lexer.nextToken();
             SQLAlterTableDropColumnItem item = new SQLAlterTableDropColumnItem();
-
+            if (lexer.token() == Token.IF) {
+                lexer.nextToken();
+                accept(Token.EXISTS);
+                item.setIfExists(true);
+            }
             SQLName name = exprParser.name();
             name.setParent(item);
             item.addColumn(name);

diff --git a/core/src/test/java/com/alibaba/druid/bvt/sql/mysql/issues/Issue5797.java b/core/src/test/java/com/alibaba/druid/bvt/sql/mysql/issues/Issue5797.java
@@ -0,0 +1,62 @@
+package com.alibaba.druid.bvt.sql.mysql.issues;
+
+import java.util.List;
+
+import com.alibaba.druid.DbType;
+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.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author lizongbo
+ * @see <a href="https://github.com/alibaba/druid/issues/5797">Issue来源</a>
+ */
+public class Issue5797 {
+
+    @Test
+    public void test_parse_create_table() {
+        for (DbType dbType : new DbType[]{
+            DbType.mysql,
+            DbType.postgresql,
+            DbType.oracle,
+            DbType.mariadb,
+            DbType.sqlserver,
+            DbType.h2,
+            DbType.hive,
+            //DbType.gaussdb,
+            //DbType.oscar,
+//            DbType.db2,
+//            DbType.dm, DbType.kingbase,
+
+        }) {
+
+            for (String sql : new String[]{
+                "-- 给课程表增加类型字段\n"
+                    + "alter table info_course drop column if exists course_type_id",
+
+            }) {
+                System.out.println(dbType + "原始的sql===" + sql);
+                SQLStatementParser parser = SQLParserUtils.createSQLStatementParser(sql, dbType);
+                List<SQLStatement> statementList = parser.parseStatementList();
+                com.alibaba.druid.sql.ast.statement.SQLJoinTableSource ggg;
+                String sqlGen = statementList.toString();
+                System.out.println(dbType + "生成的sql===" + sqlGen);
+                StringBuilder sb = new StringBuilder();
+                for (SQLStatement statement : statementList) {
+                    sb.append(statement.toString()).append(";");
+                }
+                sb.deleteCharAt(sb.length() - 1);
+                parser = SQLParserUtils.createSQLStatementParser(sb.toString(), dbType);
+                List<SQLStatement> statementListNew = parser.parseStatementList();
+                String sqlGenNew = statementList.toString();
+                System.out.println(dbType + "重新解析再生成的sql===" + sqlGenNew);
+                assertEquals(statementList.toString(), statementListNew.toString());
+            }
+        }
+    }
+}