Check MySQL version and upgrade to 9 if needed

GitHub Actions runners come with MySQL 8.0 pre-installed. The install
step was skipping installation because mysqld already existed, leaving
us with MySQL 8.0 which has authentication incompatibilities with the
test suite.

Now checks the mysqld version string. If it's below 9, stops the old
MySQL, removes old packages, clears the data directory, and installs
MySQL 9 from Oracle's deb bundle.

https://claude.ai/code/session_01CsyRwSkRxBcQoaQFVkMQsJ

Author: claude

cmd/sqlc-test-setup/main.go

@@ -57,6 +57,26 @@ func commandExists(name string) bool {
 	return err == nil
 }
 
+// isMySQLVersionOK checks if the mysqld --version output indicates MySQL 9+.
+// Example version string: "/usr/sbin/mysqld  Ver 8.0.44-0ubuntu0.24.04.2 ..."
+func isMySQLVersionOK(versionOutput string) bool {
+	// Look for "Ver X.Y.Z" pattern
+	fields := strings.Fields(versionOutput)
+	for i, f := range fields {
+		if strings.EqualFold(f, "Ver") && i+1 < len(fields) {
+			ver := strings.Split(fields[i+1], ".")
+			if len(ver) > 0 {
+				major := strings.TrimLeft(ver[0], "0")
+				if major == "" {
+					return false
+				}
+				return major[0] >= '9'
+			}
+		}
+	}
+	return false
+}
+
 // ---- install ----
 
 func runInstall() error {
@@ -129,9 +149,26 @@ func installMySQL() error {
 	if commandExists("mysqld") {
 		out, err := runOutput("mysqld", "--version")
 		if err == nil {
-			log.Printf("mysql is already installed: %s", strings.TrimSpace(out))
-			log.Println("skipping mysql installation")
-			return nil
+			version := strings.TrimSpace(out)
+			log.Printf("mysql is already installed: %s", version)
+			if isMySQLVersionOK(version) {
+				log.Println("mysql version is 9+, skipping installation")
+				return nil
+			}
+			log.Println("mysql version is too old, upgrading to MySQL 9")
+			// Stop existing MySQL before upgrading
+			_ = exec.Command("sudo", "service", "mysql", "stop").Run()
+			_ = exec.Command("sudo", "pkill", "-f", "mysqld").Run()
+			time.Sleep(2 * time.Second)
+			// Remove old MySQL packages to avoid conflicts
+			log.Println("removing old mysql packages")
+			_ = run("sudo", "apt-get", "remove", "-y", "mysql-server", "mysql-client", "mysql-common",
+				"mysql-server-core-*", "mysql-client-core-*")
+			// Clear old data directory so MySQL 9 can initialize fresh
+			log.Println("clearing old mysql data directory")
+			_ = run("sudo", "rm", "-rf", "/var/lib/mysql")
+			_ = run("sudo", "mkdir", "-p", "/var/lib/mysql")
+			_ = run("sudo", "chown", "mysql:mysql", "/var/lib/mysql")
 		}
 	}