Fix CREATE TEMPORARY TABLE command tag

The getCommandType function was returning "CREATE" instead of "CREATE TABLE"
for CREATE TEMPORARY TABLE queries. This caused incorrect command tags to be
sent to clients like Fivetran, potentially causing sync failures.

Changes:
- Fix getCommandType to return "CREATE TABLE" for:
  - CREATE TEMPORARY TABLE
  - CREATE TEMP TABLE
  - CREATE UNLOGGED TABLE
- Also fix "CREATE INDEX" for CREATE UNIQUE INDEX
- Also fix "CREATE VIEW" for CREATE OR REPLACE VIEW
- Add error logging in handleExecute for better debugging
- Add Describe operation logging for protocol debugging
- Add unit tests for CREATE TEMPORARY TABLE command types

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: EDsCODE

server/conn.go

@@ -269,7 +269,9 @@ func (c *clientConn) handleQuery(body []byte) error {
 	query := string(bytes.TrimRight(body, "\x00"))
 	query = strings.TrimSpace(query)
 
-	if query == "" {
+	// Treat empty queries or queries with just semicolons as empty
+	// PostgreSQL returns EmptyQueryResponse for queries like "" or ";" or ";;;"
+	if query == "" || isEmptyQuery(query) {
 		writeEmptyQueryResponse(c.writer)
 		writeReadyForQuery(c.writer, c.txStatus)
 		c.writer.Flush()
@@ -383,6 +385,17 @@ func (c *clientConn) handleQuery(body []byte) error {
 	return nil
 }
 
+// isEmptyQuery checks if a query contains only semicolons and whitespace.
+// PostgreSQL returns EmptyQueryResponse for queries like ";" or ";;;" or "; ; ;"
+func isEmptyQuery(query string) bool {
+	for _, r := range query {
+		if r != ';' && r != ' ' && r != '\t' && r != '\n' && r != '\r' {
+			return false
+		}
+	}
+	return true
+}
+
 // stripLeadingComments removes leading SQL comments from a query.
 // Handles both block comments /* ... */ and line comments -- ...
 func stripLeadingComments(query string) string {
@@ -458,11 +471,16 @@ func (c *clientConn) getCommandType(upperQuery string) string {
 		return "UPDATE"
 	case strings.HasPrefix(upperQuery, "DELETE"):
 		return "DELETE"
-	case strings.HasPrefix(upperQuery, "CREATE TABLE"):
+	case strings.HasPrefix(upperQuery, "CREATE TABLE"),
+		strings.HasPrefix(upperQuery, "CREATE TEMPORARY TABLE"),
+		strings.HasPrefix(upperQuery, "CREATE TEMP TABLE"),
+		strings.HasPrefix(upperQuery, "CREATE UNLOGGED TABLE"):
 		return "CREATE TABLE"
-	case strings.HasPrefix(upperQuery, "CREATE INDEX"):
+	case strings.HasPrefix(upperQuery, "CREATE INDEX"),
+		strings.HasPrefix(upperQuery, "CREATE UNIQUE INDEX"):
 		return "CREATE INDEX"
-	case strings.HasPrefix(upperQuery, "CREATE VIEW"):
+	case strings.HasPrefix(upperQuery, "CREATE VIEW"),
+		strings.HasPrefix(upperQuery, "CREATE OR REPLACE VIEW"):
 		return "CREATE VIEW"
 	case strings.HasPrefix(upperQuery, "CREATE SCHEMA"):
 		return "CREATE SCHEMA"
@@ -1136,6 +1154,8 @@ func (c *clientConn) handleDescribe(body []byte) {
 			c.sendError("ERROR", "26000", fmt.Sprintf("prepared statement %q does not exist", name))
 			return
 		}
+		log.Printf("[%s] Describe statement %q: %s", c.username, name, ps.query)
+
 		// Send parameter description based on the number of $N placeholders we found
 		// If the client didn't send explicit types, create them
 		paramTypes := ps.paramTypes
@@ -1150,7 +1170,9 @@ func (c *clientConn) handleDescribe(body []byte) {
 
 		// For queries that return results, we need to send RowDescription
 		// For other queries, send NoData
-		if !queryReturnsResults(ps.query) {
+		returnsResults := queryReturnsResults(ps.query)
+		log.Printf("[%s] Describe statement %q: returnsResults=%v", c.username, name, returnsResults)
+		if !returnsResults {
 			writeNoData(c.writer)
 			return
 		}
@@ -1295,6 +1317,7 @@ func (c *clientConn) handleExecute(body []byte) {
 		// Non-result-returning query: use Exec with converted query
 		result, err := c.db.Exec(p.stmt.convertedQuery, args...)
 		if err != nil {
+			log.Printf("[%s] Execute error: %v", c.username, err)
 			c.sendError("ERROR", "42000", err.Error())
 			c.setTxError()
 			return
@@ -1308,6 +1331,7 @@ func (c *clientConn) handleExecute(body []byte) {
 	// Result-returning query: use Query with converted query
 	rows, err := c.db.Query(p.stmt.convertedQuery, args...)
 	if err != nil {
+		log.Printf("[%s] Query error: %v", c.username, err)
 		c.sendError("ERROR", "42000", err.Error())
 		c.setTxError()
 		return
@@ -1316,6 +1340,7 @@ func (c *clientConn) handleExecute(body []byte) {
 
 	cols, err := rows.Columns()
 	if err != nil {
+		log.Printf("[%s] Columns error: %v", c.username, err)
 		c.sendError("ERROR", "42000", err.Error())
 		c.setTxError()
 		return

server/conn_test.go

@@ -4,6 +4,35 @@ import (
 	"testing"
 )
 
+func TestIsEmptyQuery(t *testing.T) {
+	tests := []struct {
+		name     string
+		query    string
+		expected bool
+	}{
+		{"empty string", "", true},
+		{"single semicolon", ";", true},
+		{"multiple semicolons", ";;;", true},
+		{"semicolons with spaces", "; ; ;", true},
+		{"semicolons with tabs", ";\t;\t;", true},
+		{"semicolons with newlines", ";\n;\n;", true},
+		{"only whitespace", "   \t\n", true},
+		{"SELECT query", "SELECT 1", false},
+		{"SELECT with semicolon", "SELECT 1;", false},
+		{"comment", "/* comment */", false},
+		{"semicolon then query", ";SELECT 1", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isEmptyQuery(tt.query)
+			if result != tt.expected {
+				t.Errorf("isEmptyQuery(%q) = %v, want %v", tt.query, result, tt.expected)
+			}
+		})
+	}
+}
+
 func TestStripLeadingComments(t *testing.T) {
 	tests := []struct {
 		name     string
@@ -112,6 +141,21 @@ func TestGetCommandType(t *testing.T) {
 			query:    "CREATE TABLE users (id INT)",
 			expected: "CREATE TABLE",
 		},
+		{
+			name:     "CREATE TEMPORARY TABLE",
+			query:    "CREATE TEMPORARY TABLE temp_users (id INT)",
+			expected: "CREATE TABLE",
+		},
+		{
+			name:     "CREATE TEMP TABLE",
+			query:    "CREATE TEMP TABLE temp_users (id INT)",
+			expected: "CREATE TABLE",
+		},
+		{
+			name:     "CREATE TEMPORARY TABLE with Fivetran comment",
+			query:    "/*Fivetran*/CREATE TEMPORARY TABLE temp_users (id INT)",
+			expected: "CREATE TABLE",
+		},
 		{
 			name:     "CREATE SCHEMA",
 			query:    "CREATE SCHEMA myschema",