# Workflow checking handshake with the database


 [Source code](handshakecwl_src.md) 


![](handshake.png)

```{contents}
---
local:
---
```

**Workflow**

## Description

This workflow executes an SQL statement to connect to the database,
display version and list tables. SQL can be overridden


## Inputs

| Name            | Type     | Default                                                                                                                                                                                | Description                                            | 
|:----------------|:---------|:---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:-------------------------------------------------------|
| database        | File     |                                                                                                                                                                                        | Path to database connection file, usually database.ini | 
| connection_name | string   |                                                                                                                                                                                        | The name of the section in the database.ini file       | 
| sql             | string[] | `["SELECT '___', version()\nUNION\nSELECT table_schema, TABLE_NAME \nFROM information_schema.tables WHERE table_schema not in ('pg_catalog', 'information_schema')\nORDER BY 1\n;\n"]` |                                                        | 

## Outputs

| Name     | Type | Description | 
|:---------|:-----|:------------|
| psql_log | File |             | 
| psql_err | File |             | 

## Steps

| Name | Runs                                    | Description | 
|:-----|:----------------------------------------|:------------|
| psql | [alter_database.cwl](alter_database.md) |             |