diff --git a/api/additional_endpoints.yaml b/api/additional_endpoints.yaml
index 123d1f8..e02420d 100644
--- a/api/additional_endpoints.yaml
+++ b/api/additional_endpoints.yaml
@@ -3,27 +3,3 @@
 #            Use plain openapi/yaml syntax, no Cheetah
 #            escaping
 # -------------------------------------------------------------------
-
-
-  /v1/overhead_advance_flat_mappings/flat/{flatId}:
-    get:
-      tags: [ "overhead_advance_flat_mapping", "flat" ]
-      summary: Returns all overhead advance mappings for a given flat
-      operationId: additional_methods.get_overhead_advance_flat_mapping_by_flat
-      parameters:
-        - name: flatId
-          in: path
-          required: true
-          schema:
-            type: integer
-      responses:
-        '200':
-          description: $table.name response
-          content:
-            'application/json':
-              schema:
-                type: array
-                items:
-                  $ref: '#/components/schemas/overhead_advance_flat_mapping'
-      security:
-      - jwt: ['secret']
diff --git a/api/additional_methods.py b/api/additional_methods.py
index 133d3ac..e69de29 100644
--- a/api/additional_methods.py
+++ b/api/additional_methods.py
@@ -1,19 +0,0 @@
-from db import dbGetMany, dbGetOne, dbInsert, dbUpdate
-from loguru import logger
-import werkzeug
-
-
-def get_overhead_advance_flat_mapping_by_flat(user, token_info, flatId=None):
-    return dbGetOne(user, token_info, {
-            "statement": """
-SELECT 
-  id
-  ,overhead_advance
-  ,flat
-  FROM overhead_advance_flat_mapping_t
-  WHERE flat = %s
-                         """, 
-            "params": (flatId, )
-        }
-    )
-
diff --git a/api/methods.py b/api/methods.py
index 0ddfb72..1164f8d 100644
--- a/api/methods.py
+++ b/api/methods.py
@@ -80,6 +80,7 @@ UPDATE account_t
     logger.warning("update_account: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
 def get_tenants(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -248,6 +249,31 @@ UPDATE tenant_t
     logger.warning("update_tenant: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
+def get_tenant_by_account(user, token_info, accountId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,salutation
+  ,firstname
+  ,lastname
+  ,address1
+  ,address2
+  ,address3
+  ,zip
+  ,city
+  ,phone1
+  ,phone2
+  ,iban
+  ,account
+  FROM tenant_t
+  WHERE account = %s
+                         """, 
+            "params": (accountId, )
+        }
+    )
+
 def get_premises(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -346,6 +372,7 @@ UPDATE premise_t
     logger.warning("update_premise: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
 def get_flats(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -445,6 +472,23 @@ UPDATE flat_t
     logger.warning("update_flat: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
+def get_flat_by_premise(user, token_info, premiseId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,premise
+  ,area
+  ,flat_no
+  FROM flat_t
+  WHERE premise = %s
+                         """, 
+            "params": (premiseId, )
+        }
+    )
+
 def get_overhead_advances(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -538,6 +582,7 @@ UPDATE overhead_advance_t
     logger.warning("update_overhead_advance: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
 def get_overhead_advance_flat_mappings(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -596,6 +641,35 @@ SELECT
     )
 
 
+
+def get_overhead_advance_flat_mapping_by_overhead_advance(user, token_info, overhead_advanceId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,overhead_advance
+  ,flat
+  FROM overhead_advance_flat_mapping_t
+  WHERE overhead_advance = %s
+                         """, 
+            "params": (overhead_advanceId, )
+        }
+    )
+
+def get_overhead_advance_flat_mapping_by_flat(user, token_info, flatId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,overhead_advance
+  ,flat
+  FROM overhead_advance_flat_mapping_t
+  WHERE flat = %s
+                         """, 
+            "params": (flatId, )
+        }
+    )
+
 def get_parkings(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -677,6 +751,21 @@ UPDATE parking_t
     logger.warning("update_parking: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
+def get_parking_by_premise(user, token_info, premiseId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,premise
+  FROM parking_t
+  WHERE premise = %s
+                         """, 
+            "params": (premiseId, )
+        }
+    )
+
 def get_commercial_premises(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -758,6 +847,21 @@ UPDATE commercial_premise_t
     logger.warning("update_commercial_premise: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
+def get_commercial_premise_by_premise(user, token_info, premiseId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,premise
+  FROM commercial_premise_t
+  WHERE premise = %s
+                         """, 
+            "params": (premiseId, )
+        }
+    )
+
 def get_tenancys(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -869,6 +973,83 @@ UPDATE tenancy_t
     logger.warning("update_tenancy: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
+def get_tenancy_by_tenant(user, token_info, tenantId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,tenant
+  ,flat
+  ,parking
+  ,commercial_premise
+  ,startdate
+  ,enddate
+  FROM tenancy_t
+  WHERE tenant = %s
+                         """, 
+            "params": (tenantId, )
+        }
+    )
+
+def get_tenancy_by_flat(user, token_info, flatId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,tenant
+  ,flat
+  ,parking
+  ,commercial_premise
+  ,startdate
+  ,enddate
+  FROM tenancy_t
+  WHERE flat = %s
+                         """, 
+            "params": (flatId, )
+        }
+    )
+
+def get_tenancy_by_parking(user, token_info, parkingId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,tenant
+  ,flat
+  ,parking
+  ,commercial_premise
+  ,startdate
+  ,enddate
+  FROM tenancy_t
+  WHERE parking = %s
+                         """, 
+            "params": (parkingId, )
+        }
+    )
+
+def get_tenancy_by_commercial_premise(user, token_info, commercial_premiseId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,tenant
+  ,flat
+  ,parking
+  ,commercial_premise
+  ,startdate
+  ,enddate
+  FROM tenancy_t
+  WHERE commercial_premise = %s
+                         """, 
+            "params": (commercial_premiseId, )
+        }
+    )
+
 def get_fees(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -968,6 +1149,7 @@ UPDATE fee_t
     logger.warning("update_fee: parameter missing: {}".format(e))
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 
+
 def get_tenancy_fee_mappings(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -1023,6 +1205,35 @@ SELECT
     )
 
 
+
+def get_tenancy_fee_mapping_by_tenancy(user, token_info, tenancyId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,tenancy
+  ,fee
+  FROM tenancy_fee_mapping_t
+  WHERE tenancy = %s
+                         """, 
+            "params": (tenancyId, )
+        }
+    )
+
+def get_tenancy_fee_mapping_by_fee(user, token_info, feeId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,tenancy
+  ,fee
+  FROM tenancy_fee_mapping_t
+  WHERE fee = %s
+                         """, 
+            "params": (feeId, )
+        }
+    )
+
 def get_account_entrys(user, token_info):
     return dbGetMany(user, token_info, {
             "statement": """
@@ -1090,3 +1301,20 @@ SELECT
     )
 
 
+
+def get_account_entry_by_account(user, token_info, accountId=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+  ,description
+  ,account
+  ,created_at
+  ,amount
+  FROM account_entry_t
+  WHERE account = %s
+                         """, 
+            "params": (accountId, )
+        }
+    )
+
diff --git a/api/methods.py.tmpl b/api/methods.py.tmpl
index 07acb70..519633b 100644
--- a/api/methods.py.tmpl
+++ b/api/methods.py.tmpl
@@ -116,4 +116,24 @@ UPDATE ${table.name}_t
     raise werkzeug.exceptions.UnprocessableEntity("parameter missing: {}".format(e))
 #end if
 
+#for $column in $table.columns
+#if (('foreignkey' in $column) and $column.foreignkey)
+
+def get_${table.name}_by_${column.name}(user, token_info, ${column.name}Id=None):
+    return dbGetOne(user, token_info, {
+            "statement": """
+SELECT 
+  id
+#for $innerColumn in $table.columns  
+  ,$innerColumn.name
+#end for
+  FROM ${table.name}_t
+  WHERE ${column.name} = %s
+                         """, 
+            "params": (${column.name}Id, )
+        }
+    )
+#end if
+#end for
+
 #end for
diff --git a/api/openapi.yaml b/api/openapi.yaml
index cffd251..953971f 100644
--- a/api/openapi.yaml
+++ b/api/openapi.yaml
@@ -191,6 +191,28 @@ paths:
                   $ref: '#/components/schemas/tenant'
       security:
       - jwt: ['secret']
+  /v1/tenants/account/{accountId}:
+    get:
+      tags: [ "tenant", "account" ]
+      summary: Return tenant by $account
+      operationId: methods.get_tenant_by_account
+      parameters:
+        - name: accountId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenant response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenant'
+      security:
+      - jwt: ['secret']
   /v1/premises:
     get:
       tags: [ "premise" ]
@@ -363,6 +385,28 @@ paths:
                   $ref: '#/components/schemas/flat'
       security:
       - jwt: ['secret']
+  /v1/flats/premise/{premiseId}:
+    get:
+      tags: [ "flat", "premise" ]
+      summary: Return flat by $premise
+      operationId: methods.get_flat_by_premise
+      parameters:
+        - name: premiseId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: flat response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/flat'
+      security:
+      - jwt: ['secret']
   /v1/overhead_advances:
     get:
       tags: [ "overhead_advance" ]
@@ -508,6 +552,50 @@ paths:
                   $ref: '#/components/schemas/overhead_advance_flat_mapping'
       security:
       - jwt: ['secret']
+  /v1/overhead_advance_flat_mappings/overhead_advance/{overhead_advanceId}:
+    get:
+      tags: [ "overhead_advance_flat_mapping", "overhead_advance" ]
+      summary: Return overhead_advance_flat_mapping by $overhead_advance
+      operationId: methods.get_overhead_advance_flat_mapping_by_overhead_advance
+      parameters:
+        - name: overhead_advanceId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: overhead_advance_flat_mapping response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/overhead_advance_flat_mapping'
+      security:
+      - jwt: ['secret']
+  /v1/overhead_advance_flat_mappings/flat/{flatId}:
+    get:
+      tags: [ "overhead_advance_flat_mapping", "flat" ]
+      summary: Return overhead_advance_flat_mapping by $flat
+      operationId: methods.get_overhead_advance_flat_mapping_by_flat
+      parameters:
+        - name: flatId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: overhead_advance_flat_mapping response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/overhead_advance_flat_mapping'
+      security:
+      - jwt: ['secret']
   /v1/parkings:
     get:
       tags: [ "parking" ]
@@ -594,6 +682,28 @@ paths:
                   $ref: '#/components/schemas/parking'
       security:
       - jwt: ['secret']
+  /v1/parkings/premise/{premiseId}:
+    get:
+      tags: [ "parking", "premise" ]
+      summary: Return parking by $premise
+      operationId: methods.get_parking_by_premise
+      parameters:
+        - name: premiseId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: parking response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/parking'
+      security:
+      - jwt: ['secret']
   /v1/commercial_premises:
     get:
       tags: [ "commercial_premise" ]
@@ -680,6 +790,28 @@ paths:
                   $ref: '#/components/schemas/commercial_premise'
       security:
       - jwt: ['secret']
+  /v1/commercial_premises/premise/{premiseId}:
+    get:
+      tags: [ "commercial_premise", "premise" ]
+      summary: Return commercial_premise by $premise
+      operationId: methods.get_commercial_premise_by_premise
+      parameters:
+        - name: premiseId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: commercial_premise response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/commercial_premise'
+      security:
+      - jwt: ['secret']
   /v1/tenancys:
     get:
       tags: [ "tenancy" ]
@@ -766,6 +898,94 @@ paths:
                   $ref: '#/components/schemas/tenancy'
       security:
       - jwt: ['secret']
+  /v1/tenancys/tenant/{tenantId}:
+    get:
+      tags: [ "tenancy", "tenant" ]
+      summary: Return tenancy by $tenant
+      operationId: methods.get_tenancy_by_tenant
+      parameters:
+        - name: tenantId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy'
+      security:
+      - jwt: ['secret']
+  /v1/tenancys/flat/{flatId}:
+    get:
+      tags: [ "tenancy", "flat" ]
+      summary: Return tenancy by $flat
+      operationId: methods.get_tenancy_by_flat
+      parameters:
+        - name: flatId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy'
+      security:
+      - jwt: ['secret']
+  /v1/tenancys/parking/{parkingId}:
+    get:
+      tags: [ "tenancy", "parking" ]
+      summary: Return tenancy by $parking
+      operationId: methods.get_tenancy_by_parking
+      parameters:
+        - name: parkingId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy'
+      security:
+      - jwt: ['secret']
+  /v1/tenancys/commercial_premise/{commercial_premiseId}:
+    get:
+      tags: [ "tenancy", "commercial_premise" ]
+      summary: Return tenancy by $commercial_premise
+      operationId: methods.get_tenancy_by_commercial_premise
+      parameters:
+        - name: commercial_premiseId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy'
+      security:
+      - jwt: ['secret']
   /v1/fees:
     get:
       tags: [ "fee" ]
@@ -911,6 +1131,50 @@ paths:
                   $ref: '#/components/schemas/tenancy_fee_mapping'
       security:
       - jwt: ['secret']
+  /v1/tenancy_fee_mappings/tenancy/{tenancyId}:
+    get:
+      tags: [ "tenancy_fee_mapping", "tenancy" ]
+      summary: Return tenancy_fee_mapping by $tenancy
+      operationId: methods.get_tenancy_fee_mapping_by_tenancy
+      parameters:
+        - name: tenancyId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy_fee_mapping response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy_fee_mapping'
+      security:
+      - jwt: ['secret']
+  /v1/tenancy_fee_mappings/fee/{feeId}:
+    get:
+      tags: [ "tenancy_fee_mapping", "fee" ]
+      summary: Return tenancy_fee_mapping by $fee
+      operationId: methods.get_tenancy_fee_mapping_by_fee
+      parameters:
+        - name: feeId
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: tenancy_fee_mapping response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/tenancy_fee_mapping'
+      security:
+      - jwt: ['secret']
   /v1/account_entrys:
     get:
       tags: [ "account_entry" ]
@@ -970,37 +1234,35 @@ paths:
                   $ref: '#/components/schemas/account_entry'
       security:
       - jwt: ['secret']
-
-# -------------------------------------------------------------------
-# ATTENTION: This file will not be parsed by Cheetah
-#            Use plain openapi/yaml syntax, no Cheetah
-#            escaping
-# -------------------------------------------------------------------
-
-
-  /v1/overhead_advance_flat_mappings/flat/{flatId}:
+  /v1/account_entrys/account/{accountId}:
     get:
-      tags: [ "overhead_advance_flat_mapping", "flat" ]
-      summary: Returns all overhead advance mappings for a given flat
-      operationId: additional_methods.get_overhead_advance_flat_mapping_by_flat
+      tags: [ "account_entry", "account" ]
+      summary: Return account_entry by $account
+      operationId: methods.get_account_entry_by_account
       parameters:
-        - name: flatId
+        - name: accountId
           in: path
           required: true
           schema:
             type: integer
       responses:
         '200':
-          description: $table.name response
+          description: account_entry response
           content:
             'application/json':
               schema:
                 type: array
                 items:
-                  $ref: '#/components/schemas/overhead_advance_flat_mapping'
+                  $ref: '#/components/schemas/account_entry'
       security:
       - jwt: ['secret']
 
+# -------------------------------------------------------------------
+# ATTENTION: This file will not be parsed by Cheetah
+#            Use plain openapi/yaml syntax, no Cheetah
+#            escaping
+# -------------------------------------------------------------------
+
 components:
   securitySchemes:
     jwt:
diff --git a/api/openapi.yaml.tmpl b/api/openapi.yaml.tmpl
index 697da27..de768eb 100644
--- a/api/openapi.yaml.tmpl
+++ b/api/openapi.yaml.tmpl
@@ -103,6 +103,32 @@ paths:
       security:
       - jwt: ['secret']
 #end if
+#for $column in $table.columns
+#if (('foreignkey' in $column) and $column.foreignkey)
+  /v1/${table.name}s/${column.name}/{${column.name}Id}:
+    get:
+      tags: [ "$table.name", "$column.name" ]
+      summary: Return $table.name by $$column.name
+      operationId: methods.get_${table.name}_by_${column.name}
+      parameters:
+        - name: ${column.name}Id
+          in: path
+          required: true
+          schema:
+            type: integer
+      responses:
+        '200':
+          description: $table.name response
+          content:
+            'application/json':
+              schema:
+                type: array
+                items:
+                  \$ref: '#/components/schemas/$table.name'
+      security:
+      - jwt: ['secret']
+#end if
+#end for
 #end for
 
 #include raw "./api/additional_endpoints.yaml"