diff --git a/packages/core/database/src/dialects/dialect.ts b/packages/core/database/src/dialects/dialect.ts
index 342f1ccc4a..d2632ab2ba 100644
--- a/packages/core/database/src/dialects/dialect.ts
+++ b/packages/core/database/src/dialects/dialect.ts
@@ -45,7 +45,7 @@ export default class Dialect {
     return true;
   }
 
-  supportsOperator(): boolean {
+  supportsOperator(operator?: string): boolean {
     return true;
   }
 
diff --git a/packages/core/database/src/metadata/index.ts b/packages/core/database/src/metadata/index.ts
index 7197a747ef..f123ddf20d 100644
--- a/packages/core/database/src/metadata/index.ts
+++ b/packages/core/database/src/metadata/index.ts
@@ -30,7 +30,7 @@ export const createMetadata = (models: Model[] = []): Metadata => {
         },
         ...model.attributes,
       },
-      lifecycles: model.lifecycles || {},
+      lifecycles: model.lifecycles ?? ({} as Meta['lifecycles']),
       indexes: model.indexes || [],
     });
   }
diff --git a/packages/core/database/src/metadata/types.ts b/packages/core/database/src/metadata/types.ts
index 5cc237aa61..a601384038 100644
--- a/packages/core/database/src/metadata/types.ts
+++ b/packages/core/database/src/metadata/types.ts
@@ -107,15 +107,10 @@ export namespace Relation {
   export type OneToOne = BaseBidirectional & {
     relation: 'oneToOne';
     useJoinTable?: boolean;
-  } & (
-      | {
-          joinTable: JoinTable;
-        }
-      | {
-          joinColumn: JoinColumn;
-          owner?: boolean;
-        }
-    );
+    joinTable?: JoinTable;
+    joinColumn?: JoinColumn;
+    owner?: boolean;
+  };
 
   export type OneToMany = BaseBidirectional & {
     relation: 'oneToMany';
@@ -124,17 +119,11 @@ export namespace Relation {
 
   export type ManyToOne = BaseBidirectional & {
     relation: 'manyToOne';
-
     useJoinTable?: boolean;
-  } & (
-      | {
-          joinTable: JoinTable;
-        }
-      | {
-          joinColumn: JoinColumn;
-          owner?: boolean;
-        }
-    );
+    joinTable?: JoinTable;
+    joinColumn?: JoinColumn;
+    owner?: boolean;
+  };
 
   export type ManyToMany = BaseBidirectional & {
     relation: 'manyToMany';
@@ -240,7 +229,7 @@ export interface Model {
   tableName: string;
   singularName: string;
   attributes: Record<string, Attribute>;
-  lifecycles: Record<string, unknown>;
+  lifecycles?: Record<Action, SubscriberFn>;
   indexes: Index[];
   componentLink?: Meta;
   columnToAttribute?: Record<string, string>;
diff --git a/packages/core/database/src/schema/schema.ts b/packages/core/database/src/schema/schema.ts
index bd6030a1fc..59c0b26f19 100644
--- a/packages/core/database/src/schema/schema.ts
+++ b/packages/core/database/src/schema/schema.ts
@@ -2,7 +2,6 @@ import * as types from '../types';
 
 import type { Metadata, Meta, Attribute } from '../metadata/types';
 import type { Column, Schema, Table } from './types';
-import { isRelationAttribute } from '../metadata/relations';
 
 const createColumn = (name: string, attribute: Attribute): Column => {
   const { type, args = [], ...opts } = getColumnType(attribute);
@@ -15,7 +14,7 @@ const createColumn = (name: string, attribute: Attribute): Column => {
     notNullable: false,
     unsigned: false,
     ...opts,
-    ...(attribute.column || {}),
+    ...('column' in attribute ? attribute.column ?? {} : {}),
   };
 };
 
@@ -31,8 +30,8 @@ const createTable = (meta: Meta): Table => {
     const attribute = meta.attributes[key];
 
     // if (types.isRelation(attribute.type)) {
-    if (isRelationAttribute(attribute)) {
-      if (attribute.morphColumn && attribute.owner) {
+    if (attribute.type === 'relation') {
+      if ('morphColumn' in attribute && attribute.morphColumn && attribute.owner) {
         const { idColumn, typeColumn } = attribute.morphColumn;
 
         table.columns.push(
@@ -45,7 +44,12 @@ const createTable = (meta: Meta): Table => {
         );
 
         table.columns.push(createColumn(typeColumn.name, { type: 'string' }));
-      } else if (attribute.joinColumn && attribute.owner && attribute.joinColumn.referencedTable) {
+      } else if (
+        'joinColumn' in attribute &&
+        attribute.joinColumn &&
+        attribute.owner &&
+        attribute.joinColumn.referencedTable
+      ) {
         // NOTE: we could pass uniquness for oneToOne to avoid creating more than one to one
 
         const { name: columnName, referencedColumn, referencedTable } = attribute.joinColumn;
@@ -73,7 +77,7 @@ const createTable = (meta: Meta): Table => {
           columns: [columnName],
         });
       }
-    } else if (types.isScalar(attribute.type)) {
+    } else if (types.isScalarAttribute(attribute)) {
       const column = createColumn(attribute.columnName || key, attribute);
 
       if (column.unique) {
@@ -100,7 +104,7 @@ const createTable = (meta: Meta): Table => {
 };
 
 const getColumnType = (attribute: Attribute) => {
-  if (attribute.columnType) {
+  if ('columnType' in attribute && attribute.columnType) {
     return attribute.columnType;
   }
 
diff --git a/packages/core/database/src/validations/relations/bidirectional.ts b/packages/core/database/src/validations/relations/bidirectional.ts
index d9fe956090..9b37fd6bb8 100644
--- a/packages/core/database/src/validations/relations/bidirectional.ts
+++ b/packages/core/database/src/validations/relations/bidirectional.ts
@@ -1,32 +1,33 @@
-import { Attribute } from '@strapi/typings';
-import * as types from '../../types';
 import { getJoinTableName } from '../../metadata/relations';
 
 import type { Database } from '../..';
+import type { Relation } from '../../metadata/types';
 
 type Link = {
-  relation: Attribute.Relation;
-  invRelation: Attribute.Relation;
+  relation: Relation.Bidirectional & { inversedBy: string };
+  invRelation: Relation.Bidirectional & { inversedBy: string };
 };
 
 const getLinksWithoutMappedBy = (db: Database): Array<Link> => {
-  const relationsToUpdate = {};
+  const relationsToUpdate: Record<string, Link> = {};
 
   db.metadata.forEach((contentType) => {
     const attributes = contentType.attributes;
 
     // For each relation attribute, add the joinTable name to tablesToUpdate
     Object.values(attributes).forEach((attribute) => {
-      if (!types.isRelation(attribute.type)) return;
+      if (attribute.type !== 'relation') {
+        return;
+      }
 
-      if (attribute.inversedBy) {
+      if ('inversedBy' in attribute && attribute.inversedBy) {
         const invRelation = db.metadata.get(attribute.target).attributes[attribute.inversedBy];
 
         // Both relations use inversedBy.
-        if (invRelation.inversedBy) {
+        if ('inversedBy' in invRelation && invRelation.inversedBy) {
           relationsToUpdate[attribute.joinTable.name] = {
-            relation: attribute,
-            invRelation,
+            relation: attribute as Relation.Bidirectional & { inversedBy: string },
+            invRelation: invRelation as Relation.Bidirectional & { inversedBy: string },
           };
         }
       }
@@ -36,12 +37,12 @@ const getLinksWithoutMappedBy = (db: Database): Array<Link> => {
   return Object.values(relationsToUpdate);
 };
 
-const isLinkTableEmpty = async (db, linkTableName) => {
+const isLinkTableEmpty = async (db: Database, linkTableName: string) => {
   // If the table doesn't exist, it's empty
   const exists = await db.getSchemaConnection().hasTable(linkTableName);
   if (!exists) return true;
 
-  const result = await db.getConnection().count('* as count').from(linkTableName);
+  const result = await db.getConnection().from(linkTableName).count('* as count');
   return Number(result[0].count) === 0;
 };