From 585728b94ea1037ddb3c009a0ff18ff62a1c3db3 Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Mon, 2 Nov 2026 18:37:17 +0000
Subject: Add test around generating SQL SELECT

---
 .../output/generators/sql/SqlGenerator.java        | 20 +++++--
 .../output/generators/sql/SqlGeneratorTests.java   | 69 ++++++++++++++++++++++
 2 files changed, 83 insertions(+), 6 deletions(-)
 create mode 100644 src/test/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGeneratorTests.java

(limited to 'src')

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGenerator.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGenerator.java
index 624b3fe..456ffd8 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGenerator.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGenerator.java
@@ -1,5 +1,6 @@
 package org.zwobble.hobgoblin.compiler.output.generators.sql;
 
+import org.zwobble.hobgoblin.compiler.ast.typed.Relation;
 import org.zwobble.hobgoblin.compiler.ast.typed.RelationTable;
 import org.zwobble.hobgoblin.compiler.ast.typed.TypedQueryDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.typed.TypedTableDefinitionNode;
@@ -56,7 +57,11 @@ public class SqlGenerator {
         TypedQueryDefinitionNode queryDefinition,
         TypesInfo typesInfo
     ) {
-        switch (queryDefinition.relation()) {
+        return generateRelation(queryDefinition.relation(), typesInfo);
+    }
+
+    SqlSelectStatement generateRelation(Relation relation, TypesInfo typesInfo) {
+        switch (relation) {
             case RelationTable relationTable -> {
                 var table = relationTable.table();
                 var schemaInfo = typesInfo.databaseSchemaInfo(table.databaseSchema());
@@ -73,14 +78,17 @@ public class SqlGenerator {
                     })
                     .toList();
 
+                // Order by the primary key to ensure stable ordering.
+                var orderBy = List.of(
+                    new SqlOrderingTerm(new SqlRef(
+                        generateColumnName(tableInfo.primaryKey().name())
+                    ))
+                );
+
                 return new SqlSelectStatement(
                     columns,
                     generateTableName(table.name()),
-                    List.of(
-                        new SqlOrderingTerm(new SqlRef(
-                            generateColumnName(tableInfo.primaryKey().name())
-                        ))
-                    )
+                    orderBy
                 );
             }
         }
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGeneratorTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGeneratorTests.java
new file mode 100644
index 0000000..0438baf
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/generators/sql/SqlGeneratorTests.java
@@ -0,0 +1,69 @@
+package org.zwobble.hobgoblin.compiler.output.generators.sql;
+
+import org.junit.jupiter.api.Test;
+import org.zwobble.hobgoblin.compiler.ast.typed.RelationTable;
+import org.zwobble.hobgoblin.compiler.builtins.NativeTypes;
+import org.zwobble.hobgoblin.compiler.output.lang.sql.ast.SqlIdentifier;
+import org.zwobble.hobgoblin.compiler.sources.NullSource;
+import org.zwobble.hobgoblin.compiler.typechecker.TypesInfoInMemory;
+import org.zwobble.hobgoblin.compiler.types.*;
+import org.zwobble.hobgoblin.compiler.util.SequencedMaps;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.zwobble.hobgoblin.compiler.output.lang.sql.ast.SqlOrderingTermMatcher.isSqlOrderingTerm;
+import static org.zwobble.hobgoblin.compiler.output.lang.sql.ast.SqlRefMatcher.isSqlRef;
+import static org.zwobble.hobgoblin.compiler.output.lang.sql.ast.SqlResultColumnMatcher.isSqlResultColumn;
+import static org.zwobble.hobgoblin.compiler.output.lang.sql.ast.SqlSelectStatementMatcher.isSqlSelectStatement;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class SqlGeneratorTests {
+    @Test
+    public void relationTableIsTranslatedToSelectFromTable() {
+        var namespaceName = NamespaceName.of("App");
+        var databaseSchema = new DatabaseSchema(namespaceName, "blog");
+        var table = new Table(databaseSchema, "authors");
+        var authorType = new SimpleStructType(namespaceName, "Author");
+        var authorIdField = new Field("id", NativeTypes.INT_32, NullSource.INSTANCE);
+        var authorNameField = new Field("name", NativeTypes.STRING, NullSource.INSTANCE);
+
+        var typesInfo = TypesInfoInMemory.empty();
+        var databaseSchemaInfo = new DatabaseSchemaInfo(SequencedMaps.ofEntries(
+            Map.entry("authors", new TableInfo(table, authorType, authorIdField))
+        ));
+        typesInfo.defineDatabaseSchema(databaseSchema, databaseSchemaInfo);
+        typesInfo.defineStructType(authorType, Optional.of(List.of(authorIdField, authorNameField)));
+
+        var sqlGenerator = new SqlGenerator();
+
+        var relation = RelationTable.arbitrary()
+            .withTable(table)
+            .build();
+
+        var statement = sqlGenerator.generateRelation(relation, typesInfo);
+
+        assertThat(statement, isSqlSelectStatement()
+            .withColumns(isSequence(
+                isSqlResultColumn()
+                    .withExpression(isSqlRef().withName(equalTo(id("id"))))
+                    .withAlias(equalTo(id("id"))),
+                isSqlResultColumn()
+                    .withExpression(isSqlRef().withName(equalTo(id("name"))))
+                    .withAlias(equalTo(id("name")))
+            ))
+            .withFrom(equalTo(id("authors")))
+            .withOrderBy(isSequence(
+                isSqlOrderingTerm()
+                    .withExpression(isSqlRef().withName(equalTo(id("id"))))
+            ))
+        );
+    }
+
+    private SqlIdentifier id(String value) {
+        return new SqlIdentifier(value);
+    }
+}
-- 
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