fix: CASE-ELSE clause is not properly parsed when a value is constant (#2238)

* fix: CASE-ELSE clause is not properly parsed when a value is constant

* fix: error message when failed to parse a type name

Author: nozaq

Diff for: internal/compiler/compat.go

@@ -96,7 +96,7 @@ func ParseTableName(node ast.Node) (*ast.TableName, error) {
 func ParseTypeName(node ast.Node) (*ast.TypeName, error) {
 	rel, err := parseRelation(node)
 	if err != nil {
-		return nil, fmt.Errorf("parse table name: %w", err)
+		return nil, fmt.Errorf("parse type name: %w", err)
 	}
 	return &ast.TypeName{
 		Catalog: rel.Catalog,

Diff for: internal/compiler/output_columns.go

@@ -157,7 +157,7 @@ func outputColumns(qc *QueryCatalog, node ast.Node) ([]*Column, error) {
 			if res.Name != nil {
 				name = *res.Name
 			}
-			// TODO: The TypeCase code has been copied from below. Instead, we
+			// TODO: The TypeCase and A_Const code has been copied from below. Instead, we
 			// need a recurse function to get the type of a node.
 			if tc, ok := n.Defresult.(*ast.TypeCast); ok {
 				if tc.TypeName == nil {
@@ -175,11 +175,18 @@ func outputColumns(qc *QueryCatalog, node ast.Node) ([]*Column, error) {
 				col.Name = name
 				cols = append(cols, col)
 			} else if aconst, ok := n.Defresult.(*ast.A_Const); ok {
-				tn, err := ParseTypeName(aconst.Val)
-				if err != nil {
-					return nil, err
+				switch aconst.Val.(type) {
+				case *ast.String:
+					cols = append(cols, &Column{Name: name, DataType: "text", NotNull: true})
+				case *ast.Integer:
+					cols = append(cols, &Column{Name: name, DataType: "int", NotNull: true})
+				case *ast.Float:
+					cols = append(cols, &Column{Name: name, DataType: "float", NotNull: true})
+				case *ast.Boolean:
+					cols = append(cols, &Column{Name: name, DataType: "bool", NotNull: true})
+				default:
+					cols = append(cols, &Column{Name: name, DataType: "any", NotNull: false})
 				}
-				cols = append(cols, &Column{Name: name, DataType: dataType(tn), NotNull: true})
 			} else {
 				cols = append(cols, &Column{Name: name, DataType: "any", NotNull: false})
 			}

Diff for: internal/endtoend/testdata/case_text/pgx/v4/go/db.go

@@ -0,0 +1,8 @@
+CREATE TABLE foo (id text not null);
+
+-- name: CaseStatementText :many
+SELECT CASE 
+  WHEN id = $1 THEN 'foo'
+  ELSE 'bar'
+END is_one
+FROM foo;

Diff for: internal/endtoend/testdata/case_text/pgx/v4/go/models.go

@@ -0,0 +1,13 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "path": "go",
+      "engine": "postgresql",
+      "sql_package": "pgx/v4",
+      "name": "querytest",
+      "schema": "query.sql",
+      "queries": "query.sql"
+    }
+  ]
+}

Diff for: internal/endtoend/testdata/case_text/pgx/v4/go/query.sql.go

@@ -0,0 +1,8 @@
+CREATE TABLE foo (id text not null);
+
+-- name: CaseStatementText :many
+SELECT CASE 
+  WHEN id = $1 THEN 'foo'
+  ELSE 'bar'
+END is_one
+FROM foo;

Diff for: internal/endtoend/testdata/case_text/pgx/v4/query.sql

@@ -0,0 +1,13 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "path": "go",
+      "engine": "postgresql",
+      "sql_package": "pgx/v5",
+      "name": "querytest",
+      "schema": "query.sql",
+      "queries": "query.sql"
+    }
+  ]
+}

Diff for: internal/endtoend/testdata/case_text/pgx/v4/sqlc.json

@@ -0,0 +1,8 @@
+CREATE TABLE foo (id text not null);
+
+-- name: CaseStatementText :many
+SELECT CASE 
+  WHEN id = $1 THEN 'foo'
+  ELSE 'bar'
+END is_one
+FROM foo;

Diff for: internal/endtoend/testdata/case_text/pgx/v5/go/db.go

@@ -0,0 +1,11 @@
+{
+  "version": "1",
+  "packages": [
+    {
+      "path": "go",
+      "name": "querytest",
+      "schema": "query.sql",
+      "queries": "query.sql"
+    }
+  ]
+}