wip: validate column names in ON CONFLICT DO UPDATE SET

- Add OnConflictClause validation in internal/sql/validate/on_conflict.go
- Integrate validation into analyze.go pipeline
- Add unit tests (5 cases)
- Add endtoend testcase for invalid column

TODO:
- Test qualified column names (cart_items.col)
- Test composite expressions on right side of SET
- Test WHERE clause in ON CONFLICT
- Test explicit schema (public.cart_items)

Author: rubensantoniorosa2704

internal/compiler/analyze.go

@@ -152,6 +152,9 @@ func (c *Compiler) _analyzeQuery(raw *ast.RawStmt, query string, failfast bool)
 		if err := check(err); err != nil {
 			return nil, err
 		}
+		if err := check(validate.OnConflictClause(c.catalog, n, table)); err != nil {
+			return nil, err
+		}
 	}
 
 	if err := check(validate.FuncCall(c.catalog, c.combo, raw)); err != nil {

internal/endtoend/testdata/on_conflict_invalid_column/postgresql/pgx/v5/query.sql

@@ -0,0 +1,6 @@
+-- name: AddItem :exec
+INSERT INTO cart_items (owner_id, product_id, price_amount, price_currency)
+VALUES ($1, $2, $3, $4)
+ON CONFLICT (owner_id, product_id) DO UPDATE
+    SET price_amount1 = EXCLUDED.price_amount1,
+        price_currency = EXCLUDED.price_currency;

internal/endtoend/testdata/on_conflict_invalid_column/postgresql/pgx/v5/schema.sql

@@ -0,0 +1,7 @@
+CREATE TABLE cart_items (
+    owner_id       VARCHAR(255) NOT NULL,
+    product_id     UUID         NOT NULL,
+    price_amount   DECIMAL      NOT NULL,
+    price_currency VARCHAR(3)   NOT NULL,
+    PRIMARY KEY (owner_id, product_id)
+);

internal/endtoend/testdata/on_conflict_invalid_column/postgresql/pgx/v5/sqlc.json

@@ -0,0 +1,17 @@
+{
+  "version": "2",
+  "sql": [
+    {
+      "engine": "postgresql",
+      "schema": "schema.sql",
+      "queries": "query.sql",
+      "gen": {
+        "go": {
+          "package": "querytest",
+          "out": "go",
+          "sql_package": "pgx/v5"
+        }
+      }
+    }
+  ]
+}

internal/endtoend/testdata/on_conflict_invalid_column/postgresql/pgx/v5/stderr.txt

@@ -0,0 +1,2 @@
+# package querytest
+query.sql:5:9: column "price_amount1" of relation "cart_items" does not exist

internal/sql/validate/on_conflict.go

@@ -0,0 +1,106 @@
+package validate
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/sqlc-dev/sqlc/internal/sql/ast"
+	"github.com/sqlc-dev/sqlc/internal/sql/astutils"
+	"github.com/sqlc-dev/sqlc/internal/sql/catalog"
+	"github.com/sqlc-dev/sqlc/internal/sql/sqlerr"
+)
+
+func OnConflictClause(cat *catalog.Catalog, stmt *ast.InsertStmt, tableName *ast.TableName) error {
+	if stmt.OnConflictClause == nil {
+		return nil
+	}
+
+	occ := stmt.OnConflictClause
+
+	if occ.Action != ast.OnConflictActionUpdate {
+		return nil
+	}
+
+	if tableName == nil {
+		return nil
+	}
+
+	tbl, err := cat.GetTable(tableName)
+	if err != nil {
+		return err
+	}
+
+	relName := ""
+	if tbl.Rel != nil {
+		relName = tbl.Rel.Name
+	}
+
+	validCols := make(map[string]struct{}, len(tbl.Columns))
+	for _, c := range tbl.Columns {
+		validCols[strings.ToLower(c.Name)] = struct{}{}
+	}
+
+	if occ.TargetList == nil {
+		return nil
+	}
+
+	for _, item := range occ.TargetList.Items {
+		res, ok := item.(*ast.ResTarget)
+		if !ok {
+			continue
+		}
+
+		if res.Name != nil {
+			colName := strings.ToLower(*res.Name)
+			if _, exists := validCols[colName]; !exists {
+				return &sqlerr.Error{
+					Code:     "42703",
+					Message:  fmt.Sprintf("column %q of relation %q does not exist", *res.Name, relName),
+					Location: res.Location,
+				}
+			}
+		}
+
+		if res.Val != nil {
+			if err := validateExcludedRefs(res.Val, validCols, relName); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func validateExcludedRefs(node ast.Node, validCols map[string]struct{}, tableName string) error {
+	refs := astutils.Search(node, func(n ast.Node) bool {
+		_, ok := n.(*ast.ColumnRef)
+		return ok
+	})
+
+	for _, ref := range refs.Items {
+		colRef, ok := ref.(*ast.ColumnRef)
+		if !ok {
+			continue
+		}
+
+		parts := make([]string, 0, len(colRef.Fields.Items))
+		for _, field := range colRef.Fields.Items {
+			if s, ok := field.(*ast.String); ok {
+				parts = append(parts, s.Str)
+			}
+		}
+
+		if len(parts) == 2 && strings.ToLower(parts[0]) == "excluded" {
+			colName := strings.ToLower(parts[1])
+			if _, exists := validCols[colName]; !exists {
+				return &sqlerr.Error{
+					Code:     "42703",
+					Message:  fmt.Sprintf("column %q does not exist in relation %q (via EXCLUDED)", parts[1], tableName),
+					Location: colRef.Location,
+				}
+			}
+		}
+	}
+
+	return nil
+}

internal/sql/validate/on_conflict_test.go

@@ -0,0 +1,130 @@
+package validate
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/sqlc-dev/sqlc/internal/engine/postgresql"
+	"github.com/sqlc-dev/sqlc/internal/sql/ast"
+	"github.com/sqlc-dev/sqlc/internal/sql/catalog"
+)
+
+func makeTestCatalog(t *testing.T) (*catalog.Catalog, *ast.TableName) {
+	t.Helper()
+
+	p := postgresql.NewParser()
+	stmts, err := p.Parse(strings.NewReader(`
+		CREATE TABLE cart_items (
+			owner_id       VARCHAR(255) NOT NULL,
+			product_id     UUID         NOT NULL,
+			price_amount   DECIMAL      NOT NULL,
+			price_currency VARCHAR(3)   NOT NULL,
+			PRIMARY KEY (owner_id, product_id)
+		);
+	`))
+	if err != nil {
+		t.Fatalf("parse schema: %v", err)
+	}
+
+	cat := catalog.New("public")
+	for _, stmt := range stmts {
+		if err := cat.Update(stmt, nil); err != nil {
+			t.Fatalf("update catalog: %v", err)
+		}
+	}
+
+	tableName := &ast.TableName{Schema: "public", Name: "cart_items"}
+	return cat, tableName
+}
+
+func makeStmt(action ast.OnConflictAction, setItems []struct{ col, val string }) *ast.InsertStmt {
+	stmt := &ast.InsertStmt{
+		Relation: &ast.RangeVar{
+			Schemaname: strPtr("public"),
+			Relname:    strPtr("cart_items"),
+		},
+	}
+
+	if action == ast.OnConflictActionNone {
+		return stmt
+	}
+
+	items := make([]ast.Node, 0, len(setItems))
+	for _, si := range setItems {
+		colName := si.col
+		items = append(items, &ast.ResTarget{
+			Name: &colName,
+			Val: &ast.ColumnRef{
+				Fields: &ast.List{
+					Items: []ast.Node{
+						&ast.String{Str: "excluded"},
+						&ast.String{Str: si.val},
+					},
+				},
+			},
+		})
+	}
+
+	stmt.OnConflictClause = &ast.OnConflictClause{
+		Action:     action,
+		TargetList: &ast.List{Items: items},
+	}
+	return stmt
+}
+
+func strPtr(s string) *string { return &s }
+
+func TestOnConflictClause(t *testing.T) {
+	cat, tableName := makeTestCatalog(t)
+
+	tests := []struct {
+		name    string
+		stmt    *ast.InsertStmt
+		wantErr bool
+	}{
+		{
+			name: "valid columns in SET and EXCLUDED",
+			stmt: makeStmt(ast.OnConflictActionUpdate, []struct{ col, val string }{
+				{"price_amount", "price_amount"},
+				{"price_currency", "price_currency"},
+			}),
+			wantErr: false,
+		},
+		{
+			name: "invalid column on left side of SET",
+			stmt: makeStmt(ast.OnConflictActionUpdate, []struct{ col, val string }{
+				{"price_amount1", "price_amount"},
+			}),
+			wantErr: true,
+		},
+		{
+			name: "invalid EXCLUDED reference on right side",
+			stmt: makeStmt(ast.OnConflictActionUpdate, []struct{ col, val string }{
+				{"price_amount", "price_amount1"},
+			}),
+			wantErr: true,
+		},
+		{
+			name:    "DO NOTHING skips column validation",
+			stmt:    makeStmt(ast.OnConflictActionNothing, nil),
+			wantErr: false,
+		},
+		{
+			name:    "no OnConflictClause passes without error",
+			stmt:    makeStmt(ast.OnConflictActionNone, nil),
+			wantErr: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := OnConflictClause(cat, tt.stmt, tableName)
+			if tt.wantErr && err == nil {
+				t.Error("expected error but got none")
+			}
+			if !tt.wantErr && err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+		})
+	}
+}