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Database Connector Generation

The SQL GENERATE CONNECTOR command auto-generates Mendix Database Connector MDL from an external database schema. This creates the entities, microflows, and configuration needed to query external databases from within a Mendix application.

Syntax

SQL <alias> GENERATE CONNECTOR INTO <module> [TABLES (<table1>, <table2>, ...)] [VIEWS (<view1>, ...)] [EXEC]

Parameters

ParameterDescription
<alias>Named connection established with SQL CONNECT
INTO <module>Target Mendix module to generate the connector in
TABLES (...)Optional: specific tables to include (default: all)
VIEWS (...)Optional: specific views to include
EXECExecute the generated MDL immediately (otherwise just output it)

Examples

Generate for All Tables

SQL CONNECT postgres 'postgres://user:pass@localhost:5432/mydb' AS source;

-- Preview the generated MDL (output only, no changes)
SQL source GENERATE CONNECTOR INTO HRModule;

Generate for Specific Tables

-- Generate for selected tables only
SQL source GENERATE CONNECTOR INTO HRModule TABLES (employees, departments);

Generate and Execute

-- Generate and immediately apply to the project
SQL source GENERATE CONNECTOR INTO HRModule
  TABLES (employees, departments)
  EXEC;

The EXEC flag executes the generated MDL against the connected project, creating the entities and microflows in one step.

What Gets Generated

The connector generation inspects the external database schema and produces:

  • Non-persistent entities for each table/view, with attributes matching column types
  • Microflow activities using EXECUTE DATABASE QUERY for querying the external database
  • SQL type mapping from database column types to Mendix attribute types

Type Mapping

External database types are mapped to Mendix types:

SQL TypeMendix Type
VARCHAR, TEXT, CHARString
INTEGER, INT, SMALLINTInteger
BIGINTLong
NUMERIC, DECIMAL, FLOAT, DOUBLEDecimal
BOOLEAN, BITBoolean
DATE, TIMESTAMP, DATETIMEDateTime
BYTEA, BLOBBinary

Workflow

-- 1. Connect to the external database
SQL CONNECT postgres 'postgres://user:pass@host:5432/db' AS source;

-- 2. Explore the schema
SQL source SHOW TABLES;
SQL source DESCRIBE employees;

-- 3. Preview the generated MDL
SQL source GENERATE CONNECTOR INTO HRModule TABLES (employees, departments);

-- 4. Review the output, then execute
SQL source GENERATE CONNECTOR INTO HRModule TABLES (employees, departments) EXEC;

-- 5. Disconnect
SQL DISCONNECT source;