45 lines
1.4 KiB
TypeScript
45 lines
1.4 KiB
TypeScript
import type { PgTableWithColumns } from 'drizzle-orm/pg-core'
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import { count, sql } from 'drizzle-orm'
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import type { BasePostgresAdapter, CountDistinct } from './types.js'
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export const countDistinct: CountDistinct = async function countDistinct(
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this: BasePostgresAdapter,
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{ column, db, joins, tableName, where },
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) {
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// When we don't have any joins - use a simple COUNT(*) query.
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if (joins.length === 0) {
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const countResult = await db
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.select({
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count: column ? count(sql`DISTINCT ${column}`) : count(),
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})
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.from(this.tables[tableName])
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.where(where)
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return Number(countResult?.[0]?.count ?? 0)
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}
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let query = db
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.select({
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count: sql`COUNT(1) OVER()`,
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})
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.from(this.tables[tableName])
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.where(where)
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.groupBy(column || this.tables[tableName].id)
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.limit(1)
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.$dynamic()
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joins.forEach(({ type, condition, table }) => {
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query = query[type ?? 'leftJoin'](table as PgTableWithColumns<any>, condition)
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})
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// When we have any joins, we need to count each individual ID only once.
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// COUNT(*) doesn't work for this well in this case, as it also counts joined tables.
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// SELECT (COUNT DISTINCT id) has a very slow performance on large tables.
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// Instead, COUNT (GROUP BY id) can be used which is still slower than COUNT(*) but acceptable.
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const countResult = await query
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return Number(countResult?.[0]?.count ?? 0)
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}
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