Fix hive view case sensitivity

fe/fe-core/src/main/java/org/apache/doris/common/util/HiveViewSqlTransformer.java

@@ -0,0 +1,66 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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 org.apache.doris.common.util;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Utility class for transforming Hive view SQL to ensure case consistency.
+ * This transformer converts SQL keywords, table names, and column names to lowercase
+ * while preserving the case of string literals enclosed in quotes.
+ */
+public class HiveViewSqlTransformer {
+
+    // Pattern to match quoted strings (both single and double quotes)
+    private static final Pattern QUOTE_PATTERN = Pattern.compile("(\"[^\"]*\"|'[^']*')");
+
+    /**
+     * Formats the input SQL by converting all non-quoted content to lowercase.
+     * This helps ensure case consistency when processing Hive view definitions,
+     * as Hive is case-insensitive but Doris may be case-sensitive in certain contexts.
+     *
+     * @param input the original SQL string from Hive view definition
+     * @return formatted SQL with non-quoted content in lowercase
+     */
+    public static String format(String input) {
+        if (input == null) {
+            return null;
+        }
+
+        Matcher quoteMatcher = QUOTE_PATTERN.matcher(input);
+        StringBuffer result = new StringBuffer();
+        int lastIndex = 0;
+
+        // Process each quoted string separately
+        while (quoteMatcher.find()) {
+            // Convert non-quoted content to lowercase
+            result.append(input.substring(lastIndex, quoteMatcher.start()).toLowerCase());
+            // Preserve quoted content as-is
+            result.append(quoteMatcher.group());
+            lastIndex = quoteMatcher.end();
+        }
+
+        // Handle remaining non-quoted content
+        if (lastIndex < input.length()) {
+            result.append(input.substring(lastIndex).toLowerCase());
+        }
+
+        return result.toString();
+    }
+}

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/analysis/BindRelation.java

@@ -33,6 +33,7 @@
 import org.apache.doris.common.Config;
 import org.apache.doris.common.IdGenerator;
 import org.apache.doris.common.Pair;
+import org.apache.doris.common.util.HiveViewSqlTransformer;
 import org.apache.doris.common.util.Util;
 import org.apache.doris.datasource.ExternalTable;
 import org.apache.doris.datasource.hive.HMSExternalTable;
@@ -413,7 +414,7 @@ private LogicalPlan getLogicalPlan(TableIf table, UnboundRelation unboundRelatio
                         isView = true;
                         String hiveCatalog = hmsTable.getCatalog().getName();
                         String hiveDb = hmsTable.getDatabase().getFullName();
-                        String ddlSql = hmsTable.getViewText();
+                        String ddlSql = HiveViewSqlTransformer.format(hmsTable.getViewText());
                         Plan hiveViewPlan = parseAndAnalyzeExternalView(
                                 hmsTable, hiveCatalog, hiveDb, ddlSql, cascadesContext);
                         return new LogicalSubQueryAlias<>(qualifiedTableName, hiveViewPlan);

fe/fe-core/src/test/java/org/apache/doris/common/util/HiveViewSqlTransformerTest.java

@@ -0,0 +1,75 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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 org.apache.doris.common.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class HiveViewSqlTransformerTest {
+
+    @Test
+    public void testFormat() {
+        // Test case 1: Simple string literal should remain unchanged
+        String sql1 = "select 'TEST1'";
+        Assert.assertEquals(sql1, HiveViewSqlTransformer.format(sql1));
+
+        // Test case 2: Mixed case SQL with double-quoted string literal
+        String sql2 = "SELECT col1, col2, col3 from test_db.TEST_TABLE where COL1 = \"TEST\"";
+        Assert.assertEquals("select col1, col2, col3 from test_db.test_table where col1 = \"TEST\"",
+                HiveViewSqlTransformer.format(sql2));
+
+        // Test case 3: Complex SQL with aggregation functions and mixed quotes
+        String sql3 = "SELECT count(col1), SUM(col2), col3, col4 from TEST_DB.TEST_TABLE GROUP BY COL3, col4 "
+                + "where COL3 = \"TEST\" and COL4='YES'";
+        Assert.assertEquals("select count(col1), sum(col2), col3, col4 from test_db.test_table group by "
+                + "col3, col4 where col3 = \"TEST\" and col4='YES'", HiveViewSqlTransformer.format(sql3));
+
+        // Test case 4: Single-quoted string literals
+        String sql4 = "SELECT COL1, COL2 from TEST_DB.TEST_TABLE where COL1 = 'TEST' and COL2='YES'";
+        Assert.assertEquals("select col1, col2 from test_db.test_table where col1 = 'TEST' and col2='YES'",
+                HiveViewSqlTransformer.format(sql4));
+
+        // Test case 5: Double-quoted string literals
+        String sql5 = "SELECT COL1, COL2 from TEST_DB.TEST_TABLE where COL1 = \"TEST\" and COL2=\"YES\"";
+        Assert.assertEquals("select col1, col2 from test_db.test_table where col1 = \"TEST\" and col2=\"YES\"",
+                HiveViewSqlTransformer.format(sql5));
+
+        // Test case 6: Mixed quote types
+        String sql6 = "SELECT COL1, COL2 from TEST_DB.TEST_TABLE where COL1 = 'TEST' and COL2=\"YES\"";
+        Assert.assertEquals("select col1, col2 from test_db.test_table where col1 = 'TEST' and col2=\"YES\"",
+                HiveViewSqlTransformer.format(sql6));
+    }
+
+    @Test
+    public void testNullInput() {
+        Assert.assertNull(HiveViewSqlTransformer.format(null));
+    }
+
+    @Test
+    public void testEmptyInput() {
+        Assert.assertEquals("", HiveViewSqlTransformer.format(""));
+    }
+
+    @Test
+    public void testComplexQuotedStrings() {
+        // Test with quoted strings containing special characters
+        String sql = "SELECT * FROM TABLE_NAME WHERE col = 'It\\'s a test' AND col2 = \"Quote \\\"test\\\"\"";
+        String expected = "select * from table_name where col = 'It\\'s a test' and col2 = \"Quote \\\"test\\\"\"";
+        Assert.assertEquals(expected, HiveViewSqlTransformer.format(sql));
+    }
+}