1 files changed, 110 insertions, 0 deletions
diff --git a/weed/query/engine/postgresql_only_test.go b/weed/query/engine/postgresql_only_test.go
new file mode 100644
index 000000000..d98cab9f0
--- /dev/null
+++ b/weed/query/engine/postgresql_only_test.go
@@ -0,0 +1,110 @@
+package engine
+
+import (
+	"context"
+	"strings"
+	"testing"
+)
+
+// TestPostgreSQLOnlySupport ensures that non-PostgreSQL syntax is properly rejected
+func TestPostgreSQLOnlySupport(t *testing.T) {
+	engine := NewTestSQLEngine()
+
+	testCases := []struct {
+		name        string
+		sql         string
+		shouldError bool
+		errorMsg    string
+		desc        string
+	}{
+		// Test that MySQL backticks are not supported for identifiers
+		{
+			name:        "MySQL_Backticks_Table",
+			sql:         "SELECT * FROM `user_events` LIMIT 1",
+			shouldError: true,
+			desc:        "MySQL backticks for table names should be rejected",
+		},
+		{
+			name:        "MySQL_Backticks_Column",
+			sql:         "SELECT `column_name` FROM user_events LIMIT 1",
+			shouldError: true,
+			desc:        "MySQL backticks for column names should be rejected",
+		},
+
+		// Test that PostgreSQL double quotes work (should NOT error)
+		{
+			name:        "PostgreSQL_Double_Quotes_OK",
+			sql:         `SELECT "user_id" FROM user_events LIMIT 1`,
+			shouldError: false,
+			desc:        "PostgreSQL double quotes for identifiers should work",
+		},
+
+		// Note: MySQL functions like YEAR(), MONTH() may parse but won't have proper implementations
+		// They're removed from the engine so they won't work correctly, but we don't explicitly reject them
+
+		// Test that PostgreSQL EXTRACT works (should NOT error)
+		{
+			name:        "PostgreSQL_EXTRACT_OK",
+			sql:         "SELECT EXTRACT(YEAR FROM CURRENT_DATE) FROM user_events LIMIT 1",
+			shouldError: false,
+			desc:        "PostgreSQL EXTRACT function should work",
+		},
+
+		// Test that single quotes work for string literals but not identifiers
+		{
+			name:        "Single_Quotes_String_Literal_OK",
+			sql:         "SELECT 'hello world' FROM user_events LIMIT 1",
+			shouldError: false,
+			desc:        "Single quotes for string literals should work",
+		},
+	}
+
+	passCount := 0
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			result, err := engine.ExecuteSQL(context.Background(), tc.sql)
+
+			if tc.shouldError {
+				// We expect this query to fail
+				if err == nil && result.Error == nil {
+					t.Errorf("❌ Expected error for %s, but query succeeded", tc.desc)
+					return
+				}
+
+				// Check for specific error message if provided
+				if tc.errorMsg != "" {
+					errorText := ""
+					if err != nil {
+						errorText = err.Error()
+					} else if result.Error != nil {
+						errorText = result.Error.Error()
+					}
+
+					if !strings.Contains(errorText, tc.errorMsg) {
+						t.Errorf("❌ Expected error containing '%s', got: %s", tc.errorMsg, errorText)
+						return
+					}
+				}
+
+				t.Logf("CORRECTLY REJECTED: %s", tc.desc)
+				passCount++
+			} else {
+				// We expect this query to succeed
+				if err != nil {
+					t.Errorf("Unexpected error for %s: %v", tc.desc, err)
+					return
+				}
+
+				if result.Error != nil {
+					t.Errorf("Unexpected result error for %s: %v", tc.desc, result.Error)
+					return
+				}
+
+				t.Logf("CORRECTLY ACCEPTED: %s", tc.desc)
+				passCount++
+			}
+		})
+	}
+
+	t.Logf("PostgreSQL-only compliance: %d/%d tests passed", passCount, len(testCases))
+}