[Enhancement] information_schema.columns support generated column exp…

…ression (backport #49712) (#49734) Signed-off-by: srlch <linzichao@starrocks.com>
StarRocks · Aug 13, 2024 · 8d4956f · 8d4956f
1 parent 7d24400
commit 8d4956f
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Showing 6 changed files with 109 additions and 3 deletions.
diff --git a/be/src/exec/schema_scanner/schema_columns_scanner.cpp b/be/src/exec/schema_scanner/schema_columns_scanner.cpp
@@ -492,7 +492,14 @@ Status SchemaColumnsScanner::fill_chunk(ChunkPtr* chunk) {
             // GENERATION_EXPRESSION
             {
                 ColumnPtr column = (*chunk)->get_column_by_slot_id(23);
-                fill_data_column_with_null(column.get());
+                if (_desc_result.columns[_column_index].columnDesc.__isset.generatedColumnExprStr &&
+                    _desc_result.columns[_column_index].columnDesc.generatedColumnExprStr.size() != 0) {
+                    std::string* str = &_desc_result.columns[_column_index].columnDesc.generatedColumnExprStr;
+                    Slice value(str->c_str(), str->length());
+                    fill_column_with_slot<TYPE_VARCHAR>(column.get(), (void*)&value);
+                } else {
+                    fill_data_column_with_null(column.get());
+                }
             }
             break;
         }

diff --git a/fe/fe-core/src/main/java/com/starrocks/catalog/Column.java b/fe/fe-core/src/main/java/com/starrocks/catalog/Column.java
@@ -778,6 +778,13 @@ public static Column read(DataInput in) throws IOException {
         return GsonUtils.GSON.fromJson(json, Column.class);
     }
 
+    public String generatedColumnExprToString() {
+        if (generatedColumnExprSerialized != null && generatedColumnExprSerialized.expressionSql != null) {
+            return SqlParser.parseSqlToExpr(generatedColumnExprSerialized.expressionSql, SqlModeHelper.MODE_DEFAULT).toSql();
+        }
+        return null;
+    }
+
     @Override
     public void gsonPostProcess() throws IOException {
         if (generatedColumnExprSerialized != null && generatedColumnExprSerialized.expressionSql != null) {

diff --git a/fe/fe-core/src/main/java/com/starrocks/service/FrontendServiceImpl.java b/fe/fe-core/src/main/java/com/starrocks/service/FrontendServiceImpl.java
@@ -1197,6 +1197,10 @@ private boolean setColumnDesc(List<TColumnDef> columns, Table table, long limit,
             }
             desc.setDataType(column.getType().toMysqlDataTypeString());
             desc.setColumnTypeStr(column.getType().toMysqlColumnTypeString());
+            String generatedColumnExprStr = column.generatedColumnExprToString();
+            if (generatedColumnExprStr != null && !generatedColumnExprStr.isEmpty()) {
+                desc.setGeneratedColumnExprStr(generatedColumnExprStr);
+            }
             final TColumnDef colDef = new TColumnDef(desc);
             final String comment = column.getComment();
             if (comment != null) {

diff --git a/gensrc/thrift/FrontendService.thrift b/gensrc/thrift/FrontendService.thrift
@@ -81,6 +81,7 @@ struct TColumnDesc {
   // Let FE control the type, which makes it easier to modify and display complex types
   26: optional string columnTypeStr
   27: optional string dataType
+  28: optional string generatedColumnExprStr
 }
 
 // A column definition; used by CREATE TABLE and DESCRIBE <table> statements. A column

diff --git a/test/sql/test_materialized_column/R/test_materialized_column b/test/sql/test_materialized_column/R/test_materialized_column
@@ -1074,4 +1074,55 @@ SELECT * FROM t;
 -- !result
 DROP DATABASE test_compaction_after_adding_generated_column;
 -- result:
--- !result
+-- !result
+-- name: test_information_schema_generated_column
+CREATE TABLE `t_information_schema_generated_column_1` (
+  `k` BIGINT NOT NULL COMMENT "",
+  `v` BIGINT AS k + 10
+) ENGINE=OLAP 
+DUPLICATE KEY(`k`)
+DISTRIBUTED BY HASH(`k`) BUCKETS 1
+PROPERTIES (
+"replication_num" = "1",
+"in_memory" = "false",
+"enable_persistent_index" = "false",
+"replicated_storage" = "false"
+);
+-- result:
+-- !result
+CREATE TABLE `t_information_schema_generated_column_2` (
+  `k` BIGINT NOT NULL COMMENT "",
+  `v` BIGINT AS k + 10
+) ENGINE=OLAP 
+DUPLICATE KEY(`k`)
+DISTRIBUTED BY HASH(`k`) BUCKETS 1
+PROPERTIES (
+"replication_num" = "1",
+"in_memory" = "false",
+"enable_persistent_index" = "false",
+"replicated_storage" = "false"
+);
+-- result:
+-- !result
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_1';
+-- result:
+k	None
+v	k + 10
+-- !result
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_2';
+-- result:
+k	None
+v	k + 10
+-- !result
+DROP TABLE t_information_schema_generated_column_1;
+-- result:
+-- !result
+DROP TABLE t_information_schema_generated_column_2;
+-- result:
+-- !result
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_1';
+-- result:
+-- !result
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_2';
+-- result:
+-- !result
diff --git a/test/sql/test_materialized_column/T/test_materialized_column b/test/sql/test_materialized_column/T/test_materialized_column
@@ -412,4 +412,40 @@ SELECT sleep(30);
 
 SELECT * FROM t;
 
-DROP DATABASE test_compaction_after_adding_generated_column;
+DROP DATABASE test_compaction_after_adding_generated_column;
+
+-- name: test_information_schema_generated_column
+CREATE TABLE `t_information_schema_generated_column_1` (
+  `k` BIGINT NOT NULL COMMENT "",
+  `v` BIGINT AS k + 10
+) ENGINE=OLAP 
+DUPLICATE KEY(`k`)
+DISTRIBUTED BY HASH(`k`) BUCKETS 1
+PROPERTIES (
+"replication_num" = "1",
+"in_memory" = "false",
+"enable_persistent_index" = "false",
+"replicated_storage" = "false"
+);
+
+CREATE TABLE `t_information_schema_generated_column_2` (
+  `k` BIGINT NOT NULL COMMENT "",
+  `v` BIGINT AS k + 10
+) ENGINE=OLAP 
+DUPLICATE KEY(`k`)
+DISTRIBUTED BY HASH(`k`) BUCKETS 1
+PROPERTIES (
+"replication_num" = "1",
+"in_memory" = "false",
+"enable_persistent_index" = "false",
+"replicated_storage" = "false"
+);
+
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_1';
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_2';
+
+DROP TABLE t_information_schema_generated_column_1;
+DROP TABLE t_information_schema_generated_column_2;
+
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_1';
+select COLUMN_NAME, GENERATION_EXPRESSION from information_schema.columns where TABLE_NAME = 't_information_schema_generated_column_2';