Fix SQLite compatibility for search-replace command

Two targeted fixes for SQLite compatibility:

1. Skip views detection on SQLite — the drop-in does not support
   SHOW FULL TABLES, and WordPress on SQLite does not use views
2. Fall back to PHP processing on SQLite for serialized data
   detection — SQLite lacks native REGEXP support

All other MySQL queries (DESCRIBE, SHOW CREATE TABLE, LIKE BINARY)
are left unchanged as the SQLite integration drop-in translates
them automatically.

Remove @skip-sqlite from 4 of 5 regex test scenarios. One scenario
(Logging with regex replace) remains skipped due to a pre-existing
difference in regex backreference behavior on SQLite.

Fixes #190

Author: dr5hn

features/search-replace.feature

@@ -222,7 +222,6 @@ Feature: Do global search/replace
       """
 
   # See https://github.com/wp-cli/search-replace-command/issues/190
-  @skip-sqlite
   Scenario: Regex search/replace
     Given a WP install
     When I run `wp search-replace '(Hello)\s(world)' '$2, $1' --regex`
@@ -962,6 +961,8 @@ Feature: Do global search/replace
     And STDERR should be empty
 
   # See https://github.com/wp-cli/search-replace-command/issues/190
+  # SQLite: regex backreference replacement produces different results due to
+  # LIKE case-sensitivity differences. Requires further investigation.
   @skip-sqlite
   Scenario: Logging with regex replace
     Given a WP install
@@ -1326,7 +1327,6 @@ Feature: Do global search/replace
       """
 
   # See https://github.com/wp-cli/search-replace-command/issues/190
-  @skip-sqlite
   Scenario: Regex search/replace with `--regex-limit=1` option
     Given a WP install
     And I run `wp post create --post_content="I have a pen, I have an apple. Pen, pine-apple, apple-pen."`
@@ -1338,7 +1338,6 @@ Feature: Do global search/replace
       """
 
   # See https://github.com/wp-cli/search-replace-command/issues/190
-  @skip-sqlite
   Scenario: Regex search/replace with `--regex-limit=2` option
     Given a WP install
     And I run `wp post create --post_content="I have a pen, I have an apple. Pen, pine-apple, apple-pen."`
@@ -1350,7 +1349,6 @@ Feature: Do global search/replace
       """
 
   # See https://github.com/wp-cli/search-replace-command/issues/190
-  @skip-sqlite
   Scenario: Regex search/replace with incorrect or default `--regex-limit`
     Given a WP install
     When I try `wp search-replace '(Hello)\s(world)' '$2, $1' --regex --regex-limit=asdf`

src/Search_Replace_Command.php

@@ -480,10 +480,16 @@ public function __invoke( $args, $assoc_args ) {
 		$tables = Utils\wp_get_table_names( $args, $assoc_args );
 
 		// Identify views so they can be skipped; views are dynamic and cannot be directly modified.
-		$views_args               = $assoc_args;
-		$views_args['views-only'] = true;
-		$views                    = Utils\wp_get_table_names( [], $views_args );
-		$view_set                 = array_flip( array_intersect( $views, $tables ) );
+		// The SQLite integration drop-in does not support SHOW FULL TABLES and WordPress
+		// on SQLite does not use views, so skip the views query entirely.
+		if ( 'sqlite' === Utils\get_db_type() ) {
+			$view_set = array();
+		} else {
+			$views_args               = $assoc_args;
+			$views_args['views-only'] = true;
+			$views                    = Utils\wp_get_table_names( [], $views_args );
+			$view_set                 = array_flip( array_intersect( $views, $tables ) );
+		}
 
 		foreach ( $tables as $table ) {
 			foreach ( $this->skip_tables as $skip_table ) {
@@ -555,12 +561,17 @@ public function __invoke( $args, $assoc_args ) {
 					$col_sql          = self::esc_sql_ident( $col );
 					$wpdb->last_error = '';
 
-					// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- escaped through self::esc_sql_ident
-					$serial_row = $wpdb->get_row( "SELECT * FROM $table_sql WHERE $col_sql REGEXP '^[aiO]:[1-9]' LIMIT 1" );
-
-					// When the regex triggers an error, we should fall back to PHP
-					if ( false !== strpos( $wpdb->last_error, 'ERROR 1139' ) ) {
+					if ( 'sqlite' === Utils\get_db_type() ) {
+						// SQLite does not support REGEXP by default, fall back to PHP processing.
 						$serial_row = true;
+					} else {
+						// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- escaped through self::esc_sql_ident
+						$serial_row = $wpdb->get_row( "SELECT * FROM $table_sql WHERE $col_sql REGEXP '^[aiO]:[1-9]' LIMIT 1" );
+
+						// When the regex triggers an error, we should fall back to PHP
+						if ( false !== strpos( $wpdb->last_error, 'ERROR 1139' ) ) {
+							$serial_row = true;
+						}
 					}
 				}