Add checks to skip table and column creation if they already exist

This commit is contained in:
Maximilian 2023-02-17 19:01:59 -06:00
parent 89d1b96400
commit 402c514970

View File

@ -36,6 +36,18 @@ func Migrate(app *app.App, anyStruct interface{}) error {
// createTable creates a table with the given name if it doesn't exist, it is assumed that id will be the primary key
func createTable(app *app.App, tableName string) error {
// Check to see if the table already exists
var tableExists bool
err := app.Db.QueryRow("SELECT EXISTS (SELECT 1 FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace WHERE c.relname ~ $1 AND pg_catalog.pg_table_is_visible(c.oid))", "^"+tableName+"$").Scan(&tableExists)
if err != nil {
log.Println("Error checking if table exists: " + tableName)
return err
}
if tableExists {
log.Println("Table already exists: " + tableName)
return nil
} else {
sanitizedTableQuery := fmt.Sprintf("CREATE TABLE IF NOT EXISTS \"%s\" (\"Id\" serial primary key)", tableName)
_, err := app.Db.Query(sanitizedTableQuery)
@ -44,12 +56,25 @@ func createTable(app *app.App, tableName string) error {
return err
}
log.Println("Table created successfully (or already exists): " + tableName)
log.Println("Table created successfully: " + tableName)
return nil
}
}
// createColumn creates a column with the given name and type if it doesn't exist
func createColumn(app *app.App, tableName, columnName, columnType string) error {
// Check to see if the column already exists
var columnExists bool
err := app.Db.QueryRow("SELECT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_name = $1 AND column_name = $2)", tableName, columnName).Scan(&columnExists)
if err != nil {
log.Println("Error checking if column exists: " + columnName + " in table: " + tableName)
return err
}
if columnExists {
log.Println("Column already exists: " + columnName + " in table: " + tableName)
return nil
} else {
postgresType, err := getPostgresType(columnType)
if err != nil {
log.Println("Error creating column: " + columnName + " in table: " + tableName + " with type: " + postgresType)
@ -65,10 +90,11 @@ func createColumn(app *app.App, tableName, columnName, columnType string) error
return err
}
log.Println("Column created successfully (or already exists):", columnName)
log.Println("Column created successfully:", columnName)
return nil
}
}
// Given a type in Go, return the corresponding type in Postgres
func getPostgresType(goType string) (string, error) {