gosora/query_gen/querygen.go

220 lines
5.3 KiB
Go

/* WIP Under Construction */
package qgen // import "github.com/Azareal/Gosora/query_gen"
import (
"database/sql"
"errors"
"strconv"
"strings"
)
var Registry []Adapter
var ErrNoAdapter = errors.New("This adapter doesn't exist")
type DBTableColumn struct {
Name string
Type string
Size int
Null bool
AutoIncrement bool
Default string
}
type DBTableKey struct {
Columns string
Type string
// Foreign keys only
FTable string
Cascade bool
}
type DBSelect struct {
Table string
Columns string
Where string
Orderby string
Limit string
}
type DBJoin struct {
Table1 string
Table2 string
Columns string
Joiners string
Where string
Orderby string
Limit string
}
type DBInsert struct {
Table string
Columns string
Fields string
}
type DBColumn struct {
Table string
Left string // Could be a function or a column, so I'm naming this Left
Alias string // aka AS Blah, if it's present
Type string // function or column
}
type DBField struct {
Name string
Type string
}
type DBWhere struct {
Expr []DBToken // Simple expressions, the innards of functions are opaque for now.
}
type DBJoiner struct {
LeftTable string
LeftColumn string
RightTable string
RightColumn string
Operator string
}
type DBOrder struct {
Column string
Order string
}
type DBToken struct {
Contents string
Type string // function, operator, column, number, string, substitute
}
type DBSetter struct {
Column string
Expr []DBToken // Simple expressions, the innards of functions are opaque for now.
}
type DBLimit struct {
Offset string // ? or int
MaxCount string // ? or int
}
type DBStmt struct {
Contents string
Type string // create-table, insert, update, delete
}
// TODO: Add the DropTable, TableExists, AddColumn, ColumnExists, and RemoveColumn methods
type Adapter interface {
GetName() string
BuildConn(config map[string]string) (*sql.DB, error)
DbVersion() string
DropTable(name string, table string) (string, error)
CreateTable(name string, table string, charset string, collation string, columns []DBTableColumn, keys []DBTableKey) (string, error)
// TODO: Some way to add indices and keys
// TODO: Test this
AddColumn(name string, table string, column DBTableColumn, key *DBTableKey) (string, error)
AddIndex(name string, table string, iname string, colname string) (string, error)
AddKey(name string, table string, column string, key DBTableKey) (string, error)
AddForeignKey(name string, table string, column string, ftable string, fcolumn string, cascade bool) (out string, e error)
SimpleInsert(name string, table string, columns string, fields string) (string, error)
SimpleUpdate(up *updatePrebuilder) (string, error)
SimpleUpdateSelect(up *updatePrebuilder) (string, error) // ! Experimental
SimpleDelete(name string, table string, where string) (string, error)
Purge(name string, table string) (string, error)
SimpleSelect(name string, table string, columns string, where string, orderby string, limit string) (string, error)
SimpleLeftJoin(name string, table1 string, table2 string, columns string, joiners string, where string, orderby string, limit string) (string, error)
SimpleInnerJoin(string, string, string, string, string, string, string, string) (string, error)
SimpleInsertSelect(string, DBInsert, DBSelect) (string, error)
SimpleInsertLeftJoin(string, DBInsert, DBJoin) (string, error)
SimpleInsertInnerJoin(string, DBInsert, DBJoin) (string, error)
SimpleCount(string, string, string, string) (string, error)
ComplexSelect(*selectPrebuilder) (string, error)
Builder() *prebuilder
Write() error
}
func GetAdapter(name string) (adap Adapter, err error) {
for _, adapter := range Registry {
if adapter.GetName() == name {
return adapter, nil
}
}
return adap, ErrNoAdapter
}
type QueryPlugin interface {
Hook(name string, args ...interface{}) error
Write() error
}
type MySQLUpsertCallback struct {
stmt *sql.Stmt
}
func (double *MySQLUpsertCallback) Exec(args ...interface{}) (res sql.Result, err error) {
if len(args) < 2 {
return res, errors.New("Need two or more arguments")
}
args = args[:len(args)-1]
return double.stmt.Exec(append(args, args...)...)
}
func PrepareMySQLUpsertCallback(db *sql.DB, query string) (*MySQLUpsertCallback, error) {
stmt, err := db.Prepare(query)
return &MySQLUpsertCallback{stmt}, err
}
type LitStr string
// TODO: Test this
func InterfaceMapToInsertStrings(data map[string]interface{}, order string) (cols string, values string) {
var done = make(map[string]bool)
var addValue = func(value interface{}) {
switch value := value.(type) {
case string:
values += "'" + strings.Replace(value, "'", "\\'", -1) + "',"
case int:
values += strconv.Itoa(value) + ","
case LitStr:
values += string(value) + ","
case bool:
if value {
values += "1,"
} else {
values += "0,"
}
}
}
// Add the ordered items
for _, col := range strings.Split(order, ",") {
col = strings.TrimSpace(col)
value, ok := data[col]
if ok {
cols += col + ","
addValue(value)
done[col] = true
}
}
// Go over any unordered items and add them at the end
if len(data) > len(done) {
for col, value := range data {
_, ok := done[col]
if ok {
continue
}
cols += col + ","
addValue(value)
}
}
if cols != "" {
cols = cols[:len(cols)-1]
values = values[:len(values)-1]
}
return cols, values
}