1package dialectquery
 2
 3import (
 4	"fmt"
 5)
 6
 7type Postgres struct{}
 8
 9var _ Querier = (*Postgres)(nil)
10
11func (p *Postgres) CreateTable(tableName string) string {
12	q := `CREATE TABLE %s (
13		id integer PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
14		version_id bigint NOT NULL,
15		is_applied boolean NOT NULL,
16		tstamp timestamp NOT NULL DEFAULT now()
17	)`
18	return fmt.Sprintf(q, tableName)
19}
20
21func (p *Postgres) InsertVersion(tableName string) string {
22	q := `INSERT INTO %s (version_id, is_applied) VALUES ($1, $2)`
23	return fmt.Sprintf(q, tableName)
24}
25
26func (p *Postgres) DeleteVersion(tableName string) string {
27	q := `DELETE FROM %s WHERE version_id=$1`
28	return fmt.Sprintf(q, tableName)
29}
30
31func (p *Postgres) GetMigrationByVersion(tableName string) string {
32	q := `SELECT tstamp, is_applied FROM %s WHERE version_id=$1 ORDER BY tstamp DESC LIMIT 1`
33	return fmt.Sprintf(q, tableName)
34}
35
36func (p *Postgres) ListMigrations(tableName string) string {
37	q := `SELECT version_id, is_applied from %s ORDER BY id DESC`
38	return fmt.Sprintf(q, tableName)
39}
40
41func (p *Postgres) GetLatestVersion(tableName string) string {
42	q := `SELECT max(version_id) FROM %s`
43	return fmt.Sprintf(q, tableName)
44}
45
46func (p *Postgres) TableExists(tableName string) string {
47	schemaName, tableName := parseTableIdentifier(tableName)
48	if schemaName != "" {
49		q := `SELECT EXISTS ( SELECT 1 FROM pg_tables WHERE schemaname = '%s' AND tablename = '%s' )`
50		return fmt.Sprintf(q, schemaName, tableName)
51	}
52	q := `SELECT EXISTS ( SELECT 1 FROM pg_tables WHERE (current_schema() IS NULL OR schemaname = current_schema()) AND tablename = '%s' )`
53	return fmt.Sprintf(q, tableName)
54}