Delete

The Delete method is part of sqac’s CRUD API and is used to Delete an existing row of the specified entity from it’s related database table. Structs annotated with ‘sqac:’ tags are colloquially known as sqac entities, hence the parameter name ‘ent’.

The ent parameter must be a pointer to a populated go struct of the sqac table declaration. If the table contains a primary-key in the database, the key column(s) should be completely populated. If an error is encountered, it will be returned to the caller.

CRUD Delete Example

The following example illustrates the deletion of an existing record (entity) from database table “depot”.

package main

import (
  "log"

  "github.com/1414C/sqac"
  _ "github.com/mattn/go-sqlite3"
)

func main() {

  var (
    Handle sqac.PublicDB
  )

  // Declare a struct to be used as the source for table creation
  type Depot struct {
    DepotNum   int       `db:"depot_num" sqac:"primary_key:inc"`
    CreateDate time.Time `db:"create_date" sqac:"nullable:false;default:now();"`
    Country    string    `db:"country" sqac:"nullable:false;default:CA"`
    Province   string    `db:"province" sqac:"nullable:false;default:AB"`
    Region     string    `db:"region" sqac:"nullable:false;default:YYC"`
    Population int       `db:"population" sqac:"nullable:false;default:0;index:non-unique"`
  }

  // Create a PublicDB instance to connect to the test sqlite db
  Handle = sqac.Create("sqlite", false, false, "testdb.sqlite")

  // Create a new table in the database
  err := Handle.DestructiveResetTables(Depot{})
  if err != nil {
    log.Errorf("%s", err.Error())
  }

  // Insert a new record into table "depot"
  var depotRecord = Depot{
      Country: "CA",
      Province: "BC",
      Region: "YVR",
      Population: 2500000,
  }
  
  err = Handle.Create(&depotRecord)
  if err != nil {
      log.Errorf(err.Error())
  } else {
      log.Println("New record: ", depotRecord)
  }

  // Delete the existing record using the fully populated depotRecord
  err = Handle.Delete(&depotRecord)
  if err != nil {
      log.Errorf(err.Error())
  }

  // Close the connection
  Handle.Close()
}