#php editor Xigua today introduces you to a correct method of using pgtypes, which is very important for developers who use Go language for PostgreSQL database programming. pgtypes is a Go language library that provides conversion and processing functions to and from PostgreSQL database types. Proper use of pgtypes can avoid errors and exceptions when dealing with database types, while also improving the readability and maintainability of your code. In this article, we'll detail how to use pgtypes correctly, as well as some common considerations and best practices. If you are a developer who uses Go language for PostgreSQL database programming, then please continue reading, I believe this article will be helpful to you.
I am developing a simple Go
service to connect to the database for basic queries. I'm using sqlc
to generate Go
functions to interact with the database. When switching the driver from lib/pq
to pgx/v5
, the types of database fields are now pgtypes
instead of Go
types . Here is an example:
instead of this:
type ListAccountsParams struct { Owner string `json:"owner"` Limit int32 `json:"limit"` Offset int32 `json:"offset"` }
I get it now:
type ListAccountsParams struct { Owner pgtype.Text `json:"owner"` Limit pgtype.Int4 `json:"limit"` Offset pgtype.Int4 `json:"offset"` }
But the only way I found using pgtypes
is this:
owner := pgtype.Text{ String: "Craigs List", Valid: true, }
Instead of just executing owner := "Craigs List"
. For numeric types it's even more overkill, all the implementations I found were like this:
pgtype.Numeric{ Int: big.NewInt(-543), Exp: 3, Status: pgtype.Present }
Using the sqlc
config file, I can override the types to support the Go
standard types, but for me the postgres text
type has to be overridden to string
There is no point in waiting...
In my opinion this is not the best way to use these types, it's counterintuitive to me. So my question is, am I doing it right? Is there a different approach? Ultimately, is there a way to configure sqlc
to use Go
types instead of pgtypes
while still using the pgx/v5
driver?
You can edit the sqlc
configuration file to specify custom types for fields that you want to use Go types instead of pgtype
types, and Override the type by specifying the required Go type in the
sqlc.yaml
types: - name: ListAccountsParams fields: - name: Owner goType: string - name: Limit goType: int32 - name: Offset goType: int32
Please note that using Go types directly may lead to potential type mismatches or other problems when interacting with the database, while pgtype
types are specifically designed to handle PostgreSQL-specific data types, and Provides a degree of type safety and compatibility!
renew
Based on your comment, when using the pgx/v5
driver with sqlc
, the generated code uses the pgtype
type to handle PostgreSQL-specific data type, which is sqlc
's default behavior when using the pgx/v5
driver, and the way you describe using pgtype
types, such as pgtype .Text
and pgtype.Int4
, is the correct way to handle these types, for example, when handling the pgtype.Text
type, you need to String
field to the desired value and the Valid
field to true
.
For numeric types, the pgtype.Numeric
type requires the Int
, Exp
, and Status
fields to be set because The pgtype.Numeric
type represents an arbitrary-precision integer value (Int
) ), an exponent (Exp
), and a status (Status
) indicating Does the value exist or is empty!
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