Support null keys via magic field

linkedin · Jul 13, 2024 · 78c03b0 · 78c03b0
1 parent 92f1864
commit 78c03b0
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Showing 3 changed files with 35 additions and 4 deletions.
diff --git a/deploy/samples/subscriptions.yaml b/deploy/samples/subscriptions.yaml
@@ -4,7 +4,7 @@ kind: Subscription
 metadata:
   name: names
 spec:
-  sql: SELECT NAME, NAME AS KEY FROM DATAGEN.PERSON
+  sql: SELECT NAME, NULL AS KEY FROM DATAGEN.PERSON
   database: RAWKAFKA
 
 
diff --git a/hoptimator-catalog/src/main/java/com/linkedin/hoptimator/catalog/ScriptImplementor.java b/hoptimator-catalog/src/main/java/com/linkedin/hoptimator/catalog/ScriptImplementor.java
@@ -171,6 +171,7 @@ public SqlNode visit(SqlCall call) {
    *
    * N.B. the following magic:
    *  - field 'PRIMARY_KEY' is treated as a PRIMARY KEY
+   *  - field 'NULL_KEY' is treated as a COMPUTED COLUMN with value NULL
    */
   class ConnectorImplementor implements ScriptImplementor {
     private final String database;
@@ -288,7 +289,11 @@ public void implement(SqlWriter w) {
     }
   }
 
-  /** Implements row type specs, e.g. `NAME VARCHAR(20), AGE INTEGER` */
+  /** Implements row type specs, e.g. `NAME VARCHAR(20), AGE INTEGER`.
+   *
+   * N.B. the following magic:
+   *  - field 'NULL_KEY' is treated as a COMPUTED COLUMN with value NULL
+   */
   class RowTypeSpecImplementor implements ScriptImplementor {
     private final RelDataType dataType;
 
@@ -308,8 +313,12 @@ public void implement(SqlWriter w) {
         .collect(Collectors.toList());
       for (int i = 0; i < fieldNames.size(); i++) {
         w.sep(",");
-        fieldNames.get(i).unparse(w, 0, 0);
-        fieldTypes.get(i).unparse(w, 0, 0);
+        if (fieldNames.get(i).toString().equals("NULL_KEY")) {
+          w.literal("KEY AS NULL");
+        } else {
+          fieldNames.get(i).unparse(w, 0, 0);
+          fieldTypes.get(i).unparse(w, 0, 0);
+        }
       } 
     }
 

diff --git a/hoptimator-catalog/src/test/java/com/linkedin/hoptimator/catalog/ScriptImplementorTest.java b/hoptimator-catalog/src/test/java/com/linkedin/hoptimator/catalog/ScriptImplementorTest.java
@@ -34,4 +34,26 @@ public void implementsFlinkCreateTableDDL() {
     assertTrue(out, out.contains("'topic'='topic1'"));
     assertFalse(out, out.contains("Row"));
   }
+
+  @Test
+  public void magicPrimaryKey() {
+    SqlWriter w = new SqlPrettyWriter();
+    RelDataType rowType = DataType.struct().with("F1", DataType.VARCHAR)
+        .with("PRIMARY_KEY", DataType.VARCHAR).rel();
+    HopTable table = new HopTable("DATABASE", "TABLE1", rowType, ConfigProvider.empty().config("x"));
+    table.implement(w);
+    String out = w.toString();
+    assertTrue(out, out.contains("PRIMARY KEY (PRIMARY_KEY)"));
+  }
+
+  @Test
+  public void magicNullKey() {
+    SqlWriter w = new SqlPrettyWriter();
+    RelDataType rowType = DataType.struct().with("F1", DataType.VARCHAR)
+        .with("NULL_KEY", DataType.VARCHAR).rel();
+    HopTable table = new HopTable("DATABASE", "TABLE1", rowType, ConfigProvider.empty().config("x"));
+    table.implement(w);
+    String out = w.toString();
+    assertTrue(out, out.contains("KEY AS NULL"));
+  }
 }