diff --git a/lib/mysql-analyzer.sh b/lib/mysql-analyzer.sh
index e3c1cb6..68008b6 100755
--- a/lib/mysql-analyzer.sh
+++ b/lib/mysql-analyzer.sh
@@ -120,8 +120,8 @@ declare -gA PROBLEM_PATTERNS=(
 
 # Map database to user and domain
 map_database_to_user_domain() {
+    [ -z "$1" ] && return 1
     local db_name="$1"
-    [ -z "$db_name" ] && return 1
     local map_file="${TEMP_SESSION_DIR}/db_user_domain_map.tmp"
 
     # Return cached if exists
@@ -155,15 +155,15 @@ map_database_to_user_domain() {
 
 # Get database owner
 get_database_owner() {
+    [ -z "$1" ] && return 1
     local db_name="$1"
-    [ -z "$db_name" ] && return 1
     map_database_to_user_domain "$db_name" | cut -d'|' -f2
 }
 
 # Get database domain
 get_database_domain() {
+    [ -z "$1" ] && return 1
     local db_name="$1"
-    [ -z "$db_name" ] && return 1
     map_database_to_user_domain "$db_name" | cut -d'|' -f3
 }
 
@@ -219,8 +219,8 @@ parse_slow_query_log() {
 
 # Identify plugin from table name
 identify_plugin_from_table() {
+    [ -z "$1" ] && return 1
     local table_name="$1"
-    [ -z "$table_name" ] && return 1
 
     # Remove prefix to get base table name
     local base_table=$(echo "$table_name" | sed 's/^[a-z0-9]*_wp_//; s/^wp_//')
@@ -244,9 +244,9 @@ identify_plugin_from_table() {
 
 # Get table size
 get_table_size() {
+    [ -z "$1" ] || [ -z "$2" ] && return 1
     local db_name="$1"
     local table_name="$2"
-    [ -z "$db_name" ] || [ -z "$table_name" ] && return 1
 
     mysql -Ns -e "SELECT ROUND(((data_length + index_length) / 1024 / 1024), 2)
                   FROM information_schema.TABLES
@@ -255,17 +255,17 @@ get_table_size() {
 
 # Get all tables for database
 get_database_tables() {
+    [ -z "$1" ] && return 1
     local db_name="$1"
-    [ -z "$db_name" ] && return 1
 
     mysql -Ns "$db_name" -e "SHOW TABLES" 2>/dev/null
 }
 
 # Analyze table for issues
 analyze_table_structure() {
+    [ -z "$1" ] || [ -z "$2" ] && return 1
     local db_name="$1"
     local table_name="$2"
-    [ -z "$db_name" ] || [ -z "$table_name" ] && return 1
 
     # Get table status
     mysql -Ns -e "SHOW TABLE STATUS FROM \`$db_name\` LIKE '$table_name'" 2>/dev/null
@@ -277,8 +277,8 @@ analyze_table_structure() {
 
 # Extract database from query
 extract_database_from_query() {
+    [ -z "$1" ] && return 1
     local query="$1"
-    [ -z "$query" ] && return 1
 
     # Try to extract from USE statement
     if echo "$query" | grep -qiE "^USE "; then