pg-info
Grabs metadata from a PostgreSQL database
Install
$ npm install pg-info --save
Usage
const pg = require('pg')
const pgInfo = require('@wmfs/pg-info')
// Make a new Postgres client
const client = new pg.Client('postgres://postgres:postgres@localhost:5432/my_test_db')
client.connect()
const info = await pgInfo({
client: client,
schemas: [
'pginfo_people_test',
'pginfo_planets_test',
'pginfo_not_exists'
]
})
API
pgInfo(options, callback)
Options:
Option | Notes |
---|---|
client |
An already-connected pg client or pg pool instance to your database |
schemas |
An array of schema names you'd like information about |
Output
Taking a look at the tests is a good place to get a feel for what pg-info will produce.
In summary, the structure of the output is:
-
info
object-
schema
object(s)-
table
object(s)-
column
object(s) -
index
object(s) -
trigger
object(s) -
fkConstraint
object(s)
-
-
view
object(s)-
column
object(s) -
trigger
object(s)
-
-
-
info
object
Example
{
generated: '2017-05-21T21:53:42.594Z',
schemas: {} // Keys are schema names
}
Properties
property | Type | Notes |
---|---|---|
generated |
string |
Timestamp of when pg-info interrogated the database |
schemas |
object |
An object where the key refers to a schema name provided via the options, and the value is a schema object |
schema
object
Example
{
schemaExistsInDatabase: true,
comment: 'Simple schema created to support testing of the pg-info package!',
tables: {...} // Keys are table names
}
Properties
property | Type | Notes |
---|---|---|
comment |
string |
The database comment added for this schema, if available |
schemaExistsInDatabase |
boolean |
Indicates if this schema is present in the database or not |
tables |
object |
An object where the key refers to a table name within this schema, and the value is a table object |
views |
object |
An object where the key refers to a view name within this schema, and the value is a view object |
table
object
Example
{
comment: 'For storing a list of planets',
pkColumnNames: [
'planet_name'
],
columns: {...}, // Keys are column names
triggers: {...}, // Keys are trigger names
indexes: {...}, // Keys are index names
fkConstraints: {...} // Keys are foreign key constraint names
}
Properties
property | Type | Notes |
---|---|---|
comment |
string |
The database comment added for this table, if available |
pkColumnNames |
[string] |
An array of column names that define this table's primary key |
columns |
object |
An object where the key refers to a column name within this table, and the value is a column object |
indexes |
object |
An object where the key refers to an index name defined for this table, and the value is an index object |
triggers |
object |
An object where the key refers to a trigger name within this table, and the value is a trigger object |
fkConstraints |
object |
An object where the key refers to a foreign-key constraint name defined for this table, and the value is a fkConstraint object |
view
object
Example
{
columns: {...}, // Keys are column names
triggers: {...}, // Keys are trigger names
comment: 'View of just those planets in our solar system',
sql: 'SELECT * FROM my_schema.planets WHERE solar_system = true;'
}
Properties
property | Type | Notes |
---|---|---|
columns |
object |
An object where the key refers to a column name within this view, and the value is a column object |
triggers |
object |
An object where the key refers to a trigger name within this view, and the value is a trigger object |
sql |
string |
The underlying SQL query of this view |
comment |
string |
The database comment added for this view, if available |
column
object
Example
{
array: false,
columnDefault: null,
isNullable: 'YES',
dataType: 'integer',
characterMaximumLength: null,
numericScale: 0,
comment: 'Age in years'
}
Properties
property | Type | Notes |
---|---|---|
array |
boolean |
Is the column an array? |
comment |
string |
The database comment added for this comment, if available |
columnDefault |
string |
The value used to default the value of this column |
isNullable |
string |
Indicates if null values are allowed in this column (YES ) or not (NO ) |
dataType |
string |
The PostgreSQL data type assigned to this column |
characterMaximumLength |
integer |
The maximum length of a string stored in this column |
numericScale |
integer |
For numeric columns, this refers to the number of digits permitted after the decimal point |
index
object
Example
{
columns: [
[
'moons_id'
]
],
unique: false,
method: 'btree'
}
Properties
property | Type | Notes |
---|---|---|
columns |
[string] |
An array that contains the column names of the table that are covered by this index |
unique |
boolean |
Indicates whether this is a unique index or not |
method |
string |
The index method used, one of btree , hash , gist or gin ) |
trigger
object
Example
{
triggers: {
someInsertTriggerName: {
eventManipulation: 'INSERT',
actionCondition: null,
actionStatement: 'EXECUTE PROCEDURE append_inserted_craters_row()',
actionOrientation: 'STATEMENT',
actionTiming: 'BEFORE'
}
}
}
Properties
property | Type | Notes |
---|---|---|
eventManipulation |
string |
Event that fires the trigger (INSERT , UPDATE , or DELETE ) |
actionCondition |
string |
WHEN condition of the trigger, null if none (also null if the table is not owned by a currently enabled role) |
actionStatement |
string |
Statement that is executed by the trigger (currently always EXECUTE PROCEDURE function(...) ) |
actionOrientation |
string |
Identifies whether the trigger fires once for each processed row or once for each statement (ROW or STATEMENT ) |
actionTiming |
string |
Time at which the trigger fires (BEFORE , AFTER , or INSTEAD OF ) |
fkConstraint
object
Example
{
targetTable: 'pginfo_planets_test.moons',
sourceColumns: [
'moons_id'
],
targetColumns: [
'id'
],
updateAction: 'NO_ACTION',
deleteAction: 'CASCADE',
matchType: 'SIMPLE'
}
Properties
property | Type | Notes |
---|---|---|
targetTable |
string |
The 'child' table that is related to this table - of the form [schemaName].[tableName]
|
sourceColumns |
[string] |
An array of foreign-key column names on this table |
targetColumns |
[string] |
And this is an array of column names found the target table (often relating to its primary key) |
updateAction |
string |
Identifies the update action, either NO ACTION , RESTRICT , CASCADE , SET NULL or SET DEFAULT
|
deleteAction |
string |
Identifies the delete action, either NO ACTION , RESTRICT , CASCADE , SET NULL or SET DEFAULT
|
matchType |
string |
Identifies the match type, either FULL , PARTIAL , or SIMPLE
|
- Note the order of the columns provided in
sourceColumns
andtargetColumns
arrays correlate with each other.
Testing
Before running these tests, you'll need a test PostgreSQL database available and set a PG_CONNECTION_STRING
environment variable to point to it, for example:
PG_CONNECTION_STRING=postgres://postgres:postgres@localhost:5432/my_test_db
$ npm test