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Developer README for the postgresql adaptor

Source: https://github.com/OpenFn/adaptors/tree/main/packages/postgresql

Language PostgreSQL

Language Pack for building expressions and operations to run PostgreSQL queries.

Documentation

required configuration for Heroku postgres

{
"host": "some-host-url.compute-1.amazonaws.com",
"port": "5432",
"database": "wouldntyouliketoknow",
"user": "me",
"password": "noway",
"ssl": true,
"allowSelfSignedCert": true
}

sql(query)

Execute an sql query. An option can be added to either log the query or not and either execute the query or no. The options can be omitted as well.

sample usage

sql(
state =>
`INSERT INTO untitled_table (name, the_geom) VALUES ('` +
dataValue('form.first_name')(state) +
`', ST_SetSRID(ST_Point(` +
dataValue('lat')(state) +
`, ` +
dataValue('long')(state) +
`),4326))`,
{ writeSql: true, execute: true }
);

Find a single value for a table

This helper function allows to build a specific query where sql would not be best suited. It returns a single value and not a promise. An example of usage would be in building a mapping object with a value from a lookup table.

alterState(async state => {
const user = {
id: 1,
name: 'Mamadou',
user_id: await findValue({
uuid: 'id',
relation: 'users',
where: { first_name: 'Mama%' },
operator: { first_name: 'like' }, // operator is optional. "=" is used by default.
})(state),
};

return upsert(...)(state);
});

Insert a single record

This functions is used to insert a single record in postgres database. An option writeSql allows to log the generated sql query. The setNull option allows to replace the specified elements with NULL.

insert(
'users',
{
email: 'antony@gmail.com',
first_name: 'Antony',
inserted_at: '2020-08-27 00:00:00',
updated_at: '2020-08-27 00:00:00',
},
{ setNull: ["''", "'undefined'"], writeSql: true, logValues: true }
);

Insert or Update using a unique column as a key

Insert or Update if matched. An option, execute, allows to either run the generated query or no.

upsert(
'users',
'email',
{
email: 'luca@openfn.org',
first_name: 'Luca',
inserted_at: '2010-01-01 00:00:00',
updated_at: '2010-01-01 00:00:00',
},
{
setNull: ["'NaN'", "'undefined'"],
writeSql: false,
execute: true,
logValues: true,
}
);

Insert or Update if a value exist in the record

This function will upsert a record only if the logical given is true. In this case we check if dataValue('name') exists.

upsertIf(dataValue('name'), 'users', 'ON CONSTRAINT users_pkey', {
name: 'Elodie',
id: 7,
});

Insert many records in postgresql

This function allows the insert of a set of records inside a table all at once.

insertMany(
'users',
state =>
state.data.people.map(s => {
return {
first_name: ['Luca', 'Mohamed', 'Elodie'],
inserted_at: '2020-01-01 00:00:00',
updated_at: '2020-01-01 00:00:00',
};
}),
{ logValues: true }
);

Upsert many records in postgresql

This function allows the upsert of a set of records inside a table all at once.

upsertMany('users', 'ON CONSTRAINT users_pkey', state =>
state.data.people.map(s => {
return {
first_name: ['Luca', 'Mohamed', 'Elodie'],
inserted_at: '2020-01-01 00:00:00',
updated_at: '2020-01-01 00:00:00',
};
})
);

Describe a table from postgres

This function is used to fetch the list of columns of a given table in the database.

describeTable('users', { writeSql: true, execute: false });

Create a table in the database

This function allows to create a table in a database from a given array of columns. The key identity can be use for a column to auto-generate a value.

insertTable('users', state =>
state.data.map(column => ({
name: column.name,
type: column.type,
required: true, // optional
unique: false, // optional - set to true for unique constraint
}))
);

Alter a table in the database

This function allows to add new columns to a table. Beware of the fact that you cannot add new columns with names that already exist in the table.

modifyTable(
'users',
state =>
state.data.map(newColumn => ({
name: newColumn.name,
type: newColumn.type,
required: true, // optional
unique: false, // optional - set to true for unique constraint
})),
{ writeSql: false, execute: true }
);

Development

Clone the adaptors monorepo. Follow the Getting Started guide inside to get set up.

Run tests using pnpm run test or pnpm run test:watch

Build the project using pnpm build.

To just build the docs run pnpm build docs