Gentity - is a codegen simple entity layer implementation

Implemented methods with database calls via github.com/jackc/pgx/v5

Features

• Insert one row
• Insert multiple rows at one query
• Update one row
• Delete one row
• Delete multiple rows at one query
• Fetch rows by simple query
• Fetch all rows of table
• Fetch row by all values of unique index
• Fetch rows by all values of non-unique index
• Fetch rows via channel
• Json struct in field (excluding indexed fields)

Update and Delete methods use primary key fields as arguments.

Primary key - is key named "primary" or shortest unique key.

All names (of structs and of fields) converted from camelCase to snake_case for database names.
Table names also use in plural form.

All methods expect context in first parameter. And pgx.Conn object under 'pgconn' name in it.

How to use

1. In package with your entity structs: //go:generate go run github.com/solta-dev/gentity
2. With each struct that has table in database:
   • Before struct: // gentity
   • For each field in unique key specify gentity-tag with it's name: gentity:"unique=primary_or_something"
   • For each field in non-unique key specify gentity-tag with it's name: gentity:"index=some_index_name"
   • For autoincrement field (if it exists) specify gentity-tag gentity:"autoincrement"
   • For some functions entity must have a primary key.
   • Example:

// gentity
type Test struct {
	ID    uint64    `gentity:"unique=primary autoincrement"`
	IntA  int       `gentity:"index=test_int_a_int_b"`
	IntB  SomeInts  `gentity:"index=test_int_a_int_b"`
	StrA  string    `gentity:"unique=test_str_a"`
	TimeA time.Time `gentity:""`
    Json  jsonType  `gentity:""`
}

If your tables names in singular form, please specify --singular flag in go:generate command

3. Prepare to use entities:

// Get connection from pgx pool
pgConn, err = pgpool.Acquire(ctx)
// Put connection to ctx (you can put pool, connection or transaction)
ctx := context.WithValue(context.Backgrond(), DBExecutorKey("dbExecutor"), pgConn.Conn())

4. Insert new row:

e := Test{IntA: 1, IntB: 1, StrA: "a", TimeA: t1}
if err = e.Insert(ctx); err != nil {
    panic(err)
}
fmt.Println("Id of new item is ", e.ID)

5. Other use cases see in test.

TODO: or not to do =)

• Tests
• Multi-row insert and delete
• Chunked queries by long arrays
• Change interface to .All() and .One for get resultset instead of channel use (or not because of with channels we can use select{} for read results simultaneous with other jobs)
• On conflict clause in multi row insert
• Custom returns clause in multi row insert
• Fetchers by begin of tree-indexes
• Make create table queries
• Make migration queries
• Caches?
• Automatic analyze table structure from DB

Alternatives

• Gorm
• Ent
• Sqlc