shelnutt2 / db2struct

Converts a mysql table into a golang struct

db2struct

The db2struct package produces a usable golang struct from a given database table for use in a .go file.

By reading details from the database about the column structure, db2struct generates a go compatible struct type with the required column names, data types, and annotations.

Generated datatypes include support for nullable columns sql.NullX types or guregu null.X types and the expected basic built in go types.

Db2Struct is based/inspired by the work of ChimeraCoder's gojson package gojson

Usage

go get github.com/Shelnutt2/db2struct/cmd/db2struct
db2struct --host localhost -d test -t test_table --package myGoPackage --struct testTable -p --user testUser

Example

MySQL table named users with four columns: id (int), user_name (varchar(255)), number_of_logins (int(11),nullable), and LAST_NAME (varchar(255), nullable)

Example below uses guregu's null package, but without the option it procuded the sql.NullInt64 and so on.

db2struct --host localhost -d example.com -t users --package example --struct user -p --user exampleUser --guregu --gorm

Output:

package example

type User struct {
  ID              int   `gorm:"column:id"`
  UserName        string `gorm:"column:user_name"`
  NumberOfLogins  null.Int `gorm:"column:number_of_logins"`
  LastName        null.String `gorm:"column:LAST_NAME"`
}

Supported Databases

Currently Supported

• MariaDB
• MySQL

Planned Support

• PostgreSQL
• Oracle
• Microsoft SQL Server

MariaDB/MySQL

Structures are created by querying the INFORMATION_SCHEMA.Columns table and then formatting the types, column names, and metadata to create a usable go compatible struct type.

NOTE: If you wish to use a unix socket instead of a TCP socket, specify the hostname as unix: then the path to the named socket. For example:

--host unix:/tmp/mysql.sock

Supported Datatypes

Currently only a limited number of MariaDB/MySQL datatypes are supported. Initial support includes:

• tinyint (sql.NullInt64 or null.Int)
• int (sql.NullInt64 or null.Int)
• smallint (sql.NullInt64 or null.Int)
• mediumint (sql.NullInt64 or null.Int)
• bigint (sql.NullInt64 or null.Int)
• decimal (sql.NullFloat64 or null.Float)
• float (sql.NullFloat64 or null.Float)
• double (sql.NullFloat64 or null.Float)
• datetime (null.Time)
• time (null.Time)
• date (null.Time)
• timestamp (null.Time)
• var (sql.String or null.String)
• enum (sql.String or null.String)
• varchar (sql.String or null.String)
• longtext (sql.String or null.String)
• mediumtext (sql.String or null.String)
• text (sql.String or null.String)
• tinytext (sql.String or null.String)
• binary
• blob
• longblob
• mediumblob
• varbinary
• json

db2struct's Issues

JSON tags should be snake cased

JSON tags should be snake cased

Support Tinyint

Support Tinyint

Support for mysql Text type

Add Support for coveralls

Add Support for coveralls

The struct tag `json` contains 'primary_key'

The bug can cause json.Marshal() output ID ,not id

Update docs

Cleanup, show usage examples, example output, add guregu null type info.

Add support for go modules

Add support for go modules

Reorganize to support multiple DB Types

Right now mysql/mariadb is hardcode. This needs to be reworked so we can support multiple db types.

• Move mysql specific util to mysql_utils.go file
• Remove hardcoded mysql commands from main.go
  • Move column select function to mysql_utils.
• Update readme and comments

Open File fail: open : no such file or directory

Open File fail: open : no such file or directory

Vertica Support

Add TableName support for gorm

If we are using gorm, TableName function needs to be defined.

Redirect output includes prompts and errors

When piping output to a file
db2struct -h host -u user -p -t whatever... >> ~/test.go
any errors messages, and the "Password:" prompt, are also sent to the file, the latter causing an apparent freeze unless you realise and press something!

You can use -p <password> on the command line which helps but does not solve the underlying issue.

Otherwise, thanks for writing this - it has saved me a heck of a lot of typing!!! Feature request - option to specify "all tables" or a list of them.

Suggestions

Can you update your tool so that it can,

1. Generate struct for all tables in a database
2. The struct name should make the first character uppercase

command not found

how to use it? when haved get ths db2struct , i run the command like:
db2struct --host localhost -d test -t test_table --package myGoPackage --struct testTable -p --user testUser
in the gopath , i get the db2struct: command not found

fields out of order

when I run db2struct the original table field order is not respected, is there a way to generate the fields where this original order is respected?

Provide CLI option for using guregu/null

Provide CLI option for using guregu/null instead of sql.Null. Perhaps tie it to the --json flag? The null package adds support for handling nulls with json.

support for omit empty option

Struct name not defaulted

If the struct name isn't passed we get a stack trace. It should be defaulted.