diff --git a/src/helpers/dynamicQueryBuilder.ts b/src/helpers/dynamicQueryBuilder.ts
index 159f518..580bbd2 100644
--- a/src/helpers/dynamicQueryBuilder.ts
+++ b/src/helpers/dynamicQueryBuilder.ts
@@ -117,7 +117,16 @@ export default abstract class DynamicQueryBuilder {
     if (queryObject.join) {
       for (const join of queryObject.join) {
         let subaffix = join.id ?? StringHelper.random(10);
-        query.leftJoin(`${alias}.${join.foreignColumn}`, `${subaffix}_${join.table}`);
+        if (join.type == undefined) join.type = "defined";
+        if (join.type == "defined") {
+          query.innerJoin(`${alias}.${join.foreignColumn}`, `${subaffix}_${join.table}`);
+        } else {
+          let condition = join.condition
+            .replaceAll(`${join.table}.`, `${subaffix}_${join.table}.`)
+            .replaceAll(`${queryObject.table}.`, `${alias}.`);
+
+          query.innerJoin(join.table, `${subaffix}_${join.table}`, condition);
+        }
 
         this.buildDynamicQuery(query, join, subaffix, depth + 1);
       }
@@ -129,7 +138,6 @@ export default abstract class DynamicQueryBuilder {
     conditions: Array<ConditionStructure>,
     alias: string
   ): void {
-    console.log(conditions, alias);
     for (const condition of conditions) {
       if (condition.structureType == "condition") {
         const whereClause = this.buildConditionClause(condition, alias);
@@ -239,8 +247,6 @@ export default abstract class DynamicQueryBuilder {
         parameters[`${parameterKey}_end`] = new Date(new Date().getFullYear() - (condition.value as number), 11, 31);
     }
 
-    console.log(query, parameters);
-
     return { query, parameters };
   }
 
@@ -417,6 +423,7 @@ const memberByRunningMembershipQuery: DynamicQueryStructure = {
       table: "membership",
       where: [{ structureType: "condition", concat: "_", operation: "null", column: "end", value: "" }],
       foreignColumn: "memberships",
+      type: "defined",
     },
   ],
   orderBy: [
diff --git a/src/type/dynamicQueries.ts b/src/type/dynamicQueries.ts
index ca6a7e5..2d870b7 100644
--- a/src/type/dynamicQueries.ts
+++ b/src/type/dynamicQueries.ts
@@ -3,7 +3,7 @@ export interface DynamicQueryStructure {
   select: string[] | "*";
   table: string;
   where?: Array<ConditionStructure>;
-  join?: Array<DynamicQueryStructure & { foreignColumn: string }>;
+  join?: Array<DynamicQueryStructure & JoinStructure>;
   orderBy?: Array<OrderByStructure>; // only at top level
 }
 
@@ -48,6 +48,8 @@ export type WhereOperation =
   | "timespanEq"; // Date before x years (YYYY-01-01 <bis> YYYY-12-31)
 // TODO: age between | age equals | age greater | age smaller
 
+export type JoinStructure = { foreignColumn: string; type: "defined" } | { condition: string; type: "custom" };
+
 export type OrderByStructure = {
   id: string;
   depth: number;
@@ -101,18 +103,21 @@ export const exampleQuery: DynamicQueryStructure = {
       select: "*",
       table: "communication",
       foreignColumn: "sendNewsletter",
+      type: "defined",
     },
     {
       id: "91011",
       select: "*",
       table: "membership",
       foreignColumn: "memberships",
+      type: "defined",
       join: [
         {
           id: "121314",
           select: "*",
           table: "membership_status",
           foreignColumn: "status",
+          type: "defined",
           where: [
             {
               structureType: "condition",