func NewJSONUnquote(json sql.Expression) sql.Expression {
	return &JSONUnquote{expression.UnaryExpression{Child: json}}
}
NewJSONUnquote creates a new JSONUnquote UDF.
package function
import (
	"bytes"
	"encoding/binary"
	"encoding/hex"
	"fmt"
	"reflect"
	"unicode/utf8"
	"github.com/src-d/go-mysql-server/sql"
	"github.com/src-d/go-mysql-server/sql/expression"
)
type JSONUnquote struct {
	expression.UnaryExpression
}