[Improve](struct)improve struct support into outfile

be/src/vec/runtime/vfile_result_writer.cpp

@@ -383,6 +383,10 @@ Status VFileResultWriter::_write_csv_file(const Block& block) {
                     _plain_text_outstream << col.type->to_string(*col.column, i);
                     break;
                 }
+                case TYPE_STRUCT: {
+                    _plain_text_outstream << col.type->to_string(*col.column, i);
+                    break;
+                }
                 default: {
                     // not supported type, like BITMAP, just export null
                     _plain_text_outstream << NULL_IN_CSV;

regression-test/suites/export/test_struct_export.groovy

@@ -0,0 +1,135 @@
+// 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.
+
+import org.codehaus.groovy.runtime.IOGroovyMethods
+
+import java.nio.charset.StandardCharsets
+import java.nio.file.Files
+import java.nio.file.Paths
+
+suite("test_struct_export", "export") {
+    // check whether the FE config 'enable_outfile_to_local' is true
+    StringBuilder strBuilder = new StringBuilder()
+    strBuilder.append("curl --location-trusted -u " + context.config.jdbcUser + ":" + context.config.jdbcPassword)
+    strBuilder.append(" http://" + context.config.feHttpAddress + "/rest/v1/config/fe")
+
+    String command = strBuilder.toString()
+    def process = command.toString().execute()
+    def code = process.waitFor()
+    def err = IOGroovyMethods.getText(new BufferedReader(new InputStreamReader(process.getErrorStream())));
+    def out = process.getText()
+    logger.info("Request FE Config: code=" + code + ", out=" + out + ", err=" + err)
+    assertEquals(code, 0)
+    def response = parseJson(out.trim())
+    assertEquals(response.code, 0)
+    assertEquals(response.msg, "success")
+    def configJson = response.data.rows
+    boolean enableOutfileToLocal = false
+    for (Object conf: configJson) {
+        assert conf instanceof Map
+        if (((Map<String, String>) conf).get("Name").toLowerCase() == "enable_outfile_to_local") {
+            enableOutfileToLocal = ((Map<String, String>) conf).get("Value").toLowerCase() == "true"
+        }
+    }
+    if (!enableOutfileToLocal) {
+        logger.warn("Please set enable_outfile_to_local to true to run test_outfile")
+        return
+    }
+
+    // define the table
+    def testTable = "tbl_test_struct_export"
+
+    sql "DROP TABLE IF EXISTS ${testTable}"
+    sql "ADMIN SET FRONTEND CONFIG ('enable_struct_type' = 'true')"
+
+    sql """
+        CREATE TABLE IF NOT EXISTS ${testTable} (
+                      `k1` INT(11) NULL,
+                      `k2` STRUCT<f1:BOOLEAN,f2:TINYINT,f3:SMALLINT,f4:INT,f5:INT,f6:BIGINT,f7:LARGEINT> NULL,
+                      `k3` STRUCT<f1:FLOAT,f2:DOUBLE,f3:DECIMAL(3,3)> NULL,
+                      `k4` STRUCT<f1:DATE,f2:DATETIME,f3:DATEV2,f4:DATETIMEV2> NULL,
+                      `k5` STRUCT<f1:CHAR(10),f2:VARCHAR(10),f3:STRING> NOT NULL
+        )
+        DUPLICATE KEY(k1)
+        DISTRIBUTED BY HASH(k1) BUCKETS 10
+        PROPERTIES("replication_num" = "1");
+        """
+
+    // make data
+    sql "INSERT INTO ${testTable} VALUES(1, {1,11,111,1111,11111,11111,111111},null,null,{'','',''})"
+    sql "INSERT INTO ${testTable} VALUES(2, {null,null,null,null,null,null,null},{2.1,2.22,0.333},null,{null,null,null})"
+    sql "INSERT INTO ${testTable} VALUES(3, null,{null,null,null},{'2023-02-23','2023-02-23 00:10:19','2023-02-23','2023-02-23 00:10:19'},{'','',''})"
+    sql "INSERT INTO ${testTable} VALUES(4, null,null,{null,null,null,null},{'abc','def','hij'})"
+
+    // check result
+    qt_select """ SELECT * FROM ${testTable} ORDER BY k1; """
+    qt_select_count """SELECT COUNT(k2), COUNT(k4) FROM ${testTable}"""
+
+    def outFilePath = """${context.file.parent}/test_struct_export"""
+    logger.info("test_struct_export the outFilePath=" + outFilePath)
+    // struct select into outfile
+    try {
+        File path = new File(outFilePath)
+        if (!path.exists()) {
+            assert path.mkdirs()
+        } else {
+            throw new IllegalStateException("""${outFilePath} already exists! """)
+        }
+        sql """
+                    SELECT * FROM ${testTable} ORDER BY k1 INTO OUTFILE "file://${outFilePath}/";
+        """
+        File[] files = path.listFiles()
+        assert files.length == 1
+
+        List<String> outLines = Files.readAllLines(Paths.get(files[0].getAbsolutePath()), StandardCharsets.UTF_8)
+        assert outLines.size() == 4
+        for (int r = 0; r < outLines.size(); r++) {
+            String[] outLine = outLines.get(r).split("\t")
+            logger.info("test_struct_export: " + outLines.get(r))
+            assert outLine.size() == 5
+            // check NULL
+            if (outLine[0] == 1) {
+                assert outLine[1] == "{1,11,111,1111,11111,11111,111111}"
+                assert outline[2] == "\\N"
+                assert outline[3] == "\\N"
+                assert outline[4] == "{'','',''}"
+            }
+            if (outLine[0] == 2) {
+                assert outLine[1] == "{null,null,null,null,null,null,null},{2.1,2.22,2.333},null,{null,null,null})"
+                assert outLine[2] == "{2.1,2.22,2.333}"
+                assert outline[3] == "\\N"
+                assert outline[4] == "{null,null,null}"
+            }
+            if (outLine[0] == 3) {
+                assert outLine[1] == "\\N"
+                assert outline[2] == "{null,null,null}"
+                assert outline[3] == "{'2023-02-23','2023-02-23 00:10:19','2023-02-23','2023-02-23 00:10:19'}"
+                assert outline[4] == "{'','',''}"
+            }
+
+        }
+    } finally {
+        try_sql("DROP TABLE IF EXISTS ${testTable}")
+        File path = new File(outFilePath)
+        if (path.exists()) {
+            for (File f : path.listFiles()) {
+                f.delete();
+            }
+            path.delete();
+        }
+    }
+}