diff --git a/packages/core/database/lib/query/helpers/where.js b/packages/core/database/lib/query/helpers/where.js
index 0d367f65cf..b66375d4f2 100644
--- a/packages/core/database/lib/query/helpers/where.js
+++ b/packages/core/database/lib/query/helpers/where.js
@@ -19,8 +19,6 @@ const OPERATORS = [
   '$null',
   '$notNull',
   '$between',
-  // '$like',
-  // '$regexp',
   '$startsWith',
   '$endsWith',
   '$contains',
@@ -214,17 +212,6 @@ const applyOperator = (qb, column, operator, value) => {
       qb.whereBetween(column, value);
       break;
     }
-    // case '$regexp': {
-    //   // TODO:
-    //
-    // break;
-    // }
-    // // string
-    // // TODO: use $case to make it case insensitive
-    // case '$like': {
-    //   qb.where(column, 'like', value);
-    // break;
-    // }
 
     // TODO: add casting logic
     case '$startsWith': {
@@ -316,9 +303,10 @@ const applyWhere = (qb, where) => {
 
 const fieldLowerFn = qb => {
   // Postgres requires string to be passed
-  if (qb.client.config.client === 'pg') {
+  if (qb.client.config.client === 'postgres') {
     return 'LOWER(CAST(?? AS VARCHAR))';
   }
+
   return 'LOWER(??)';
 };
 
diff --git a/packages/core/database/lib/query/query-builder.js b/packages/core/database/lib/query/query-builder.js
index 62feafc7b9..e21148141b 100644
--- a/packages/core/database/lib/query/query-builder.js
+++ b/packages/core/database/lib/query/query-builder.js
@@ -253,10 +253,12 @@ const createQueryBuilder = (uid, db) => {
         qb.groupBy(state.groupBy);
       }
 
+      // if there are joins and it is a delete or update use a sub query
       if (state.where) {
         helpers.applyWhere(qb, state.where);
       }
 
+      // if there are joins and it is a delete or update use a sub query
       if (state.search) {
         qb.where(subQb => {
           helpers.applySearch(subQb, state.search, { alias: this.alias, db, uid });
diff --git a/packages/core/strapi/tests/filtering.test.e2e.js b/packages/core/strapi/tests/filtering.test.e2e.js
index e3b7c0e7fa..b180e970dc 100644
--- a/packages/core/strapi/tests/filtering.test.e2e.js
+++ b/packages/core/strapi/tests/filtering.test.e2e.js
@@ -236,7 +236,7 @@ describe('Filtering API', () => {
           qs: {
             filters: {
               name: {
-                $contains: 'product',
+                $containsi: 'product',
               },
             },
           },
@@ -252,7 +252,7 @@ describe('Filtering API', () => {
           qs: {
             filters: {
               name: {
-                $contains: 'PrOdUct',
+                $containsi: 'PrOdUct',
               },
             },
           },
@@ -268,7 +268,7 @@ describe('Filtering API', () => {
           qs: {
             filters: {
               name: {
-                $contains: 'production',
+                $containsi: 'production',
               },
             },
           },
@@ -282,7 +282,7 @@ describe('Filtering API', () => {
           qs: {
             filters: {
               name: {
-                $contains: 'ProdUctIon',
+                $containsi: 'ProdUctIon',
               },
             },
           },
@@ -300,7 +300,7 @@ describe('Filtering API', () => {
           qs: {
             filters: {
               name: {
-                $notContains: 'production',
+                $notContainsi: 'production',
               },
             },
           },
@@ -315,7 +315,7 @@ describe('Filtering API', () => {
           url: '/products',
           qs: {
             filters: {
-              name: { $notContains: 'ProdUctIon' },
+              name: { $notContainsi: 'ProdUctIon' },
             },
           },
         });
@@ -329,7 +329,7 @@ describe('Filtering API', () => {
           url: '/products',
           qs: {
             filters: {
-              name: { $notContains: 'product' },
+              name: { $notContainsi: 'product' },
             },
           },
         });
@@ -341,7 +341,7 @@ describe('Filtering API', () => {
           url: '/products',
           qs: {
             filters: {
-              name: { $notContains: 'ProDuCt' },
+              name: { $notContainsi: 'ProDuCt' },
             },
           },
         });