Two tables, metadata and view_events, each have columns for config_id and config_type. The goal is to retrieve all unique view_events based on a user's email address, distinct by config_id and config_type, ordered by timestamp in descending order, limited to the 10 most recent entries. Although the following knex.js code attempts to achieve this, it faces issues:
return dbClient<AuthenticatedUserIndexRow>(METADATA_TABLE_NAME)
.select([
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.CONFIG_ID}`,
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.CONFIG_TYPE}`,
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.DESCRIPTION}`,
`${VIEW_EVENTS_TABLE_NAME}.${VIEW_EVENTS_COLUMNS.TIMESTAMP}`,
])
.innerJoin<AuthenticatedUserIndexRow>(VIEW_EVENTS_TABLE_NAME, function innerJoinOnViewEvents() {
this.on(
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.STORAGE_ID}`,
'=',
`${VIEW_EVENTS_TABLE_NAME}.${VIEW_EVENTS_COLUMNS.CONFIG_STORAGE_ID}`,
)
.andOn(
`${VIEW_EVENTS_TABLE_NAME}.${VIEW_EVENTS_COLUMNS.USER_EMAIL}`,
'=',
rawSql('?', [authUserEmail]),
)
.andOn(`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.DELETED}`, '=', rawSql('?', [false]));
})
.distinct([
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.CONFIG_TYPE}`,
`${METADATA_TABLE_NAME}.${METADATA_COLUMNS.CONFIG_ID}`,
])
.limit(EVENT_LIMIT)
.orderBy(VIEW_EVENTS_COLUMNS.TIMESTAMP, 'desc');
Consider the sample tables provided:
view_events
+-------------+-----------+--------------------------+----------------------+
| config_type | config_id | timestamp | email |
+-------------+-----------+--------------------------+----------------------+
| a | foo | 2020-01-23T03:08:14.618Z | johndoe@example.com |
| a | bar | 2020-01-23T03:08:13.618Z | janedoe@example.com |
| b | foo | 2020-01-23T03:08:12.618Z | bobdoe@example.com |
+-------------+-----------+--------------------------+----------------------+
metadata
+-------------+-----------+---------------------------+
| config_type | config_id | description |
+-------------+-----------+---------------------------+
| a | foo | Type a config with id foo |
| a | bar | Type a config with id bar |
| b | foo | Type b config with id foo |
+-------------+-----------+---------------------------+
If the authUserEmail is johndoe@example.com, the desired output should be as follows:
+-------------+-----------+---------------------------+
| config_type | config_id | description |
+-------------+-----------+---------------------------+
| a | foo | Type a config with id foo |
| a | bar | Type a config with id bar |
| b | foo | Type b config with id foo |
+-------------+-----------+---------------------------+
While attempting this query, an issue arose due to the combination of SELECT and DISTINCT. What would be the correct approach here?