diff --git a/packages/cli/generators/relation/base-relation.generator.js b/packages/cli/generators/relation/base-relation.generator.js
index 3a9ba0a0bf36..12dbacb27431 100644
--- a/packages/cli/generators/relation/base-relation.generator.js
+++ b/packages/cli/generators/relation/base-relation.generator.js
@@ -99,6 +99,8 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
       type: this._getRepositoryRelationPropertyType(),
     };
 
+    if (classDeclaration.getProperty(property.name)) return;
+
     // already checked the existence of property before
     relationUtils.addProperty(classDeclaration, property);
   }
diff --git a/packages/cli/generators/relation/belongs-to-relation.generator.js b/packages/cli/generators/relation/belongs-to-relation.generator.js
index f5a1d46e180d..befb393bb719 100644
--- a/packages/cli/generators/relation/belongs-to-relation.generator.js
+++ b/packages/cli/generators/relation/belongs-to-relation.generator.js
@@ -95,7 +95,9 @@ module.exports = class BelongsToRelationGenerator extends (
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
     // this checks if the foreign key already exists, so the 2nd param should be foreignKeyName
-    relationUtils.doesRelationExist(sourceClass, foreignKeyName);
+    relationUtils.doesRelationExist(sourceClass, foreignKeyName, {
+      force: this.options.force,
+    });
 
     const modelProperty = this.getBelongsTo(
       targetModel,
diff --git a/packages/cli/generators/relation/has-many-relation.generator.js b/packages/cli/generators/relation/has-many-relation.generator.js
index 4d56c005f0c2..8e71f1111277 100644
--- a/packages/cli/generators/relation/has-many-relation.generator.js
+++ b/packages/cli/generators/relation/has-many-relation.generator.js
@@ -99,7 +99,9 @@ module.exports = class HasManyRelationGenerator extends BaseRelationGenerator {
       sourceModel,
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
-    relationUtils.doesRelationExist(sourceClass, relationName);
+    relationUtils.doesRelationExist(sourceClass, relationName, {
+      force: this.options.force,
+    });
 
     modelProperty = this.getHasMany(
       targetModel,
@@ -121,6 +123,20 @@ module.exports = class HasManyRelationGenerator extends BaseRelationGenerator {
     );
     const targetClass = relationUtils.getClassObj(targetFile, targetModel);
 
+    if (isForeignKeyExist) {
+      const existingFK = targetClass.getProperty(foreignKeyName);
+      if (
+        existingFK &&
+        !relationUtils.isValidPropertyType(targetClass, foreignKeyName, fktype)
+      ) {
+        existingFK.remove();
+        const newFK = relationUtils.addForeignKey(foreignKeyName, fktype);
+        relationUtils.addProperty(targetClass, newFK);
+        targetClass.formatText();
+        await targetFile.save();
+      }
+    }
+
     if (isForeignKeyExist) {
       if (
         !relationUtils.isValidPropertyType(targetClass, foreignKeyName, fktype)
diff --git a/packages/cli/generators/relation/has-many-through-relation.generator.js b/packages/cli/generators/relation/has-many-through-relation.generator.js
index a7cb949595cd..c7d8d40c56e9 100644
--- a/packages/cli/generators/relation/has-many-through-relation.generator.js
+++ b/packages/cli/generators/relation/has-many-through-relation.generator.js
@@ -133,7 +133,9 @@ module.exports = class HasManyThroughRelationGenerator extends (
       sourceModel,
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
-    relationUtils.doesRelationExist(sourceClass, relationName);
+    relationUtils.doesRelationExist(sourceClass, relationName, {
+      force: this.options.force,
+    });
     // add the relation to the source model
     const isDefaultSourceKey = sourceKey === dftSourceKey;
     const isDefaultTargetKey = targetKey === dftTargetKey;
diff --git a/packages/cli/generators/relation/has-one-relation.generator.js b/packages/cli/generators/relation/has-one-relation.generator.js
index 2c4585ced1c0..8fd8b0cbc1fc 100644
--- a/packages/cli/generators/relation/has-one-relation.generator.js
+++ b/packages/cli/generators/relation/has-one-relation.generator.js
@@ -96,7 +96,9 @@ module.exports = class HasOneRelationGenerator extends BaseRelationGenerator {
       sourceModel,
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
-    relationUtils.doesRelationExist(sourceClass, relationName);
+    relationUtils.doesRelationExist(sourceClass, relationName, {
+      force: this.options.force,
+    });
 
     modelProperty = this.getHasOne(
       targetModel,
@@ -122,6 +124,20 @@ module.exports = class HasOneRelationGenerator extends BaseRelationGenerator {
     );
     const targetClass = relationUtils.getClassObj(targetFile, targetModel);
 
+    if (isForeignKeyExist) {
+      const existingFK = targetClass.getProperty(foreignKeyName);
+      if (
+        existingFK &&
+        !relationUtils.isValidPropertyType(targetClass, foreignKeyName, fktype)
+      ) {
+        existingFK.remove();
+        const newFK = relationUtils.addForeignKey(foreignKeyName, fktype);
+        relationUtils.addProperty(targetClass, newFK);
+        targetClass.formatText();
+        await targetFile.save();
+      }
+    }
+
     if (isForeignKeyExist) {
       if (
         !relationUtils.isValidPropertyType(targetClass, foreignKeyName, fktype)
diff --git a/packages/cli/generators/relation/index.js b/packages/cli/generators/relation/index.js
index 0c7cb5703e50..c37c1b72efa1 100644
--- a/packages/cli/generators/relation/index.js
+++ b/packages/cli/generators/relation/index.js
@@ -603,7 +603,11 @@ module.exports = class RelationGenerator extends ArtifactGenerator {
           this.artifactInfo.relationType === 'referencesMany')
       ) {
         try {
-          relationUtils.doesRelationExist(cl, this.artifactInfo.foreignKeyName);
+          relationUtils.doesRelationExist(
+            cl,
+            this.artifactInfo.foreignKeyName,
+            {force: this.options.force},
+          );
         } catch (err) {
           /* istanbul ignore next */
           this.exit(err);
@@ -682,6 +686,19 @@ module.exports = class RelationGenerator extends ArtifactGenerator {
         ? PROMPT_MESSAGE_RELATION_NAME
         : PROMPT_MESSAGE_PROPERTY_NAME;
 
+    if (!this.options.relationName)
+      this.artifactInfo.relationName = this.artifactInfo.defaultRelationName;
+    if (
+      (this.artifactInfo.relationType === 'hasMany' ||
+        this.artifactInfo.relationType === 'hasManyThrough') &&
+      this.options.relationName &&
+      !this.options.relationName.endsWith('s')
+    ) {
+      this.artifactInfo.relationName = utils.pluralize(
+        this.artifactInfo.relationName,
+      );
+    }
+
     return this.prompt([
       {
         type: 'string',
diff --git a/packages/cli/generators/relation/references-many-relation.generator.js b/packages/cli/generators/relation/references-many-relation.generator.js
index dc55fe69abef..8a91ca37084b 100644
--- a/packages/cli/generators/relation/references-many-relation.generator.js
+++ b/packages/cli/generators/relation/references-many-relation.generator.js
@@ -41,7 +41,9 @@ module.exports = class ReferencesManyRelationGenerator extends (
     );
     const sourceClass = relationUtils.getClassObj(sourceFile, sourceModel);
     // this checks if the foreign key already exists, so the 2nd param should be foreignKeyName
-    relationUtils.doesRelationExist(sourceClass, foreignKeyName);
+    relationUtils.doesRelationExist(sourceClass, foreignKeyName, {
+      force: this.options.force,
+    });
 
     const modelProperty = this.getReferencesMany(
       targetModel,
diff --git a/packages/cli/generators/relation/utils.generator.js b/packages/cli/generators/relation/utils.generator.js
index 7fc6cc6efde9..bc35282e487b 100644
--- a/packages/cli/generators/relation/utils.generator.js
+++ b/packages/cli/generators/relation/utils.generator.js
@@ -114,22 +114,26 @@ exports.doesPropertyExist = function (classObj, propertyName) {
     .includes(propertyName);
 };
 
-exports.doesRelationExist = function (classObj, propertyName) {
+exports.doesRelationExist = function (classObj, propertyName, options = {}) {
+  const force = options.force;
   if (this.doesPropertyExist(classObj, propertyName)) {
     // If the property is decorated by `@property()`,
     // turn it to be a relational property decorated by `@belongsTo()`
     const decorators = classObj.getProperty(propertyName).getDecorators();
     const hasPropertyDecorator =
       decorators.length > 0 && decorators[0].getName() === 'property';
-    // If it's already decorated by a relational decorator,
-    // throw error
-    if (!hasPropertyDecorator) {
-      throw new Error(
-        'relational property ' +
-          propertyName +
-          ' already exist in the model ' +
-          classObj.getName(),
-      );
+    if (!force) {
+      // If it's already decorated by a relational decorator,
+      // throw error
+      if (!hasPropertyDecorator) {
+        throw new Error(
+          'relational property ' +
+            propertyName +
+            ' already exist in the model ' +
+            classObj.getName() +
+            ' Use --force to overwrite it',
+        );
+      }
     }
 
     this.deleteProperty(classObj.getProperty(propertyName));