prepared_statements.md

Prepared Statements

You can use Prepared Statements on Athena.

How to use

  db, _ := sql.Open("athena", "db=default&output_location=s3://results")
  
  // 1. Prepare 
  stmt, _ := db.PrepareContext(ctx, "SELECT url, code FROM cloudfront WHERE code = ?")
  defer stmt.Close() // 3. Close
 
  // 2. Execute
  rows, _ := stmt.QueryContext(ctx, targetCode)
  defer rows.Close()
  
  for rows.Next() {
    var url string
    var code int
    rows.Scan(&url, &code)
  }

1. Prepare

• Run PREPARE on Athena to create a Statement for use with Athena
• Create a Stmt object and keep statement_name inside
  • The stmt object is valid until Close method is executed
• Result Mode
  • Available under all Result Modes
  • ResultMode can be specified in PrepareContext

    rows, _ := stmt.PrepareContext(SetDLMode(ctx), sql) // Prepares a statement in DL Mode
    

2. Execute

• Run a prepared statement using EXECUTE on Athena
• You can specify parameters
• Use QueryContext and ExecContext methods

3. Close

• Run DEALLOCATE PREPARE and delete the prepared statement
• Use the Close method of the Stmt object

Examples

intParam := 1
stringParam := "string value"
stmt, _ := db.PrepareContext(ctx, "SELECT * FROM test_table WHERE int_column = ? AND string_column = ?")
rows, _ := stmt.QueryContext(ctx, intParam, stringParam)

execute SELECT * FROM test_table WHERE int_column = 1 and string_column = 'string value'