459 lines
11 KiB
Go
459 lines
11 KiB
Go
/*
|
|
*
|
|
* Query Generator Library
|
|
* WIP Under Construction
|
|
* Copyright Azareal 2017 - 2020
|
|
*
|
|
*/
|
|
package qgen
|
|
|
|
import (
|
|
"os"
|
|
"strings"
|
|
)
|
|
|
|
// TODO: Add support for numbers and strings?
|
|
func processColumns(colStr string) (columns []DBColumn) {
|
|
if colStr == "" {
|
|
return columns
|
|
}
|
|
colStr = strings.Replace(colStr, " as ", " AS ", -1)
|
|
for _, segment := range strings.Split(colStr, ",") {
|
|
var outCol DBColumn
|
|
dotHalves := strings.Split(strings.TrimSpace(segment), ".")
|
|
|
|
var halves []string
|
|
if len(dotHalves) == 2 {
|
|
outCol.Table = dotHalves[0]
|
|
halves = strings.Split(dotHalves[1], " AS ")
|
|
} else {
|
|
halves = strings.Split(dotHalves[0], " AS ")
|
|
}
|
|
|
|
halves[0] = strings.TrimSpace(halves[0])
|
|
if len(halves) == 2 {
|
|
outCol.Alias = strings.TrimSpace(halves[1])
|
|
}
|
|
if halves[0][len(halves[0])-1] == ')' {
|
|
outCol.Type = TokenFunc
|
|
} else if halves[0] == "?" {
|
|
outCol.Type = TokenSub
|
|
} else {
|
|
outCol.Type = TokenColumn
|
|
}
|
|
|
|
outCol.Left = halves[0]
|
|
columns = append(columns, outCol)
|
|
}
|
|
return columns
|
|
}
|
|
|
|
// TODO: Allow order by statements without a direction
|
|
func processOrderby(orderStr string) (order []DBOrder) {
|
|
if orderStr == "" {
|
|
return order
|
|
}
|
|
for _, segment := range strings.Split(orderStr, ",") {
|
|
var outOrder DBOrder
|
|
halves := strings.Split(strings.TrimSpace(segment), " ")
|
|
if len(halves) != 2 {
|
|
continue
|
|
}
|
|
outOrder.Column = halves[0]
|
|
outOrder.Order = strings.ToLower(halves[1])
|
|
order = append(order, outOrder)
|
|
}
|
|
return order
|
|
}
|
|
|
|
func processJoiner(joinStr string) (joiner []DBJoiner) {
|
|
if joinStr == "" {
|
|
return joiner
|
|
}
|
|
joinStr = strings.Replace(joinStr, " on ", " ON ", -1)
|
|
joinStr = strings.Replace(joinStr, " and ", " AND ", -1)
|
|
for _, segment := range strings.Split(joinStr, " AND ") {
|
|
var outJoin DBJoiner
|
|
var parseOffset int
|
|
var left, right string
|
|
|
|
left, parseOffset = getIdentifier(segment, parseOffset)
|
|
outJoin.Operator, parseOffset = getOperator(segment, parseOffset+1)
|
|
right, parseOffset = getIdentifier(segment, parseOffset+1)
|
|
|
|
leftColumn := strings.Split(left, ".")
|
|
rightColumn := strings.Split(right, ".")
|
|
outJoin.LeftTable = strings.TrimSpace(leftColumn[0])
|
|
outJoin.RightTable = strings.TrimSpace(rightColumn[0])
|
|
outJoin.LeftColumn = strings.TrimSpace(leftColumn[1])
|
|
outJoin.RightColumn = strings.TrimSpace(rightColumn[1])
|
|
|
|
joiner = append(joiner, outJoin)
|
|
}
|
|
return joiner
|
|
}
|
|
|
|
func (wh *DBWhere) parseNumber(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
if '0' <= ch && ch <= '9' {
|
|
buffer += string(ch)
|
|
} else {
|
|
i--
|
|
wh.Expr = append(wh.Expr, DBToken{buffer, TokenNumber})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (wh *DBWhere) parseColumn(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
switch {
|
|
case ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ch == '.' || ch == '_':
|
|
buffer += string(ch)
|
|
case ch == '(':
|
|
return wh.parseFunction(segment, buffer, i)
|
|
default:
|
|
i--
|
|
wh.Expr = append(wh.Expr, DBToken{buffer, TokenColumn})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (wh *DBWhere) parseFunction(segment string, buffer string, i int) int {
|
|
preI := i
|
|
i = skipFunctionCall(segment, i-1)
|
|
buffer += segment[preI:i] + string(segment[i])
|
|
wh.Expr = append(wh.Expr, DBToken{buffer, TokenFunc})
|
|
return i
|
|
}
|
|
|
|
func (wh *DBWhere) parseString(segment string, i int) int {
|
|
var buffer string
|
|
i++
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
if ch != '\'' {
|
|
buffer += string(ch)
|
|
} else {
|
|
wh.Expr = append(wh.Expr, DBToken{buffer, TokenString})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (wh *DBWhere) parseOperator(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
if isOpByte(ch) {
|
|
buffer += string(ch)
|
|
} else {
|
|
i--
|
|
wh.Expr = append(wh.Expr, DBToken{buffer, TokenOp})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
// TODO: Make this case insensitive
|
|
func normalizeAnd(in string) string {
|
|
in = strings.Replace(in, " and ", " AND ", -1)
|
|
return strings.Replace(in, " && ", " AND ", -1)
|
|
}
|
|
func normalizeOr(in string) string {
|
|
in = strings.Replace(in, " or ", " OR ", -1)
|
|
return strings.Replace(in, " || ", " OR ", -1)
|
|
}
|
|
|
|
// TODO: Write tests for this
|
|
func processWhere(whereStr string) (where []DBWhere) {
|
|
if whereStr == "" {
|
|
return where
|
|
}
|
|
whereStr = normalizeAnd(whereStr)
|
|
whereStr = normalizeOr(whereStr)
|
|
|
|
for _, seg := range strings.Split(whereStr, " AND ") {
|
|
tmpWhere := &DBWhere{[]DBToken{}}
|
|
seg += ")"
|
|
for i := 0; i < len(seg); i++ {
|
|
ch := seg[i]
|
|
switch {
|
|
case '0' <= ch && ch <= '9':
|
|
i = tmpWhere.parseNumber(seg, i)
|
|
// TODO: Sniff the third byte offset from char or it's non-existent to avoid matching uppercase strings which start with OR
|
|
case ch == 'O' && (i+1) < len(seg) && seg[i+1] == 'R':
|
|
tmpWhere.Expr = append(tmpWhere.Expr, DBToken{"OR", TokenOr})
|
|
i += 1
|
|
case ch == 'N' && (i+2) < len(seg) && seg[i+1] == 'O' && seg[i+2] == 'T':
|
|
tmpWhere.Expr = append(tmpWhere.Expr, DBToken{"NOT", TokenNot})
|
|
i += 2
|
|
case ch == 'L' && (i+3) < len(seg) && seg[i+1] == 'I' && seg[i+2] == 'K' && seg[i+3] == 'E':
|
|
tmpWhere.Expr = append(tmpWhere.Expr, DBToken{"LIKE", TokenLike})
|
|
i += 3
|
|
case ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ch == '_':
|
|
i = tmpWhere.parseColumn(seg, i)
|
|
case ch == '\'':
|
|
i = tmpWhere.parseString(seg, i)
|
|
case ch == ')' && i < (len(seg)-1):
|
|
tmpWhere.Expr = append(tmpWhere.Expr, DBToken{")", TokenOp})
|
|
case isOpByte(ch):
|
|
i = tmpWhere.parseOperator(seg, i)
|
|
case ch == '?':
|
|
tmpWhere.Expr = append(tmpWhere.Expr, DBToken{"?", TokenSub})
|
|
}
|
|
}
|
|
where = append(where, *tmpWhere)
|
|
}
|
|
return where
|
|
}
|
|
|
|
func (set *DBSetter) parseNumber(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
if '0' <= ch && ch <= '9' {
|
|
buffer += string(ch)
|
|
} else {
|
|
set.Expr = append(set.Expr, DBToken{buffer, TokenNumber})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (set *DBSetter) parseColumn(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
switch {
|
|
case ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ch == '_':
|
|
buffer += string(ch)
|
|
case ch == '(':
|
|
return set.parseFunction(segment, buffer, i)
|
|
default:
|
|
i--
|
|
set.Expr = append(set.Expr, DBToken{buffer, TokenColumn})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (set *DBSetter) parseFunction(segment string, buffer string, i int) int {
|
|
preI := i
|
|
i = skipFunctionCall(segment, i-1)
|
|
buffer += segment[preI:i] + string(segment[i])
|
|
set.Expr = append(set.Expr, DBToken{buffer, TokenFunc})
|
|
return i
|
|
}
|
|
|
|
func (set *DBSetter) parseString(segment string, i int) int {
|
|
var buffer string
|
|
i++
|
|
for ; i < len(segment); i++ {
|
|
char := segment[i]
|
|
if char != '\'' {
|
|
buffer += string(char)
|
|
} else {
|
|
set.Expr = append(set.Expr, DBToken{buffer, TokenString})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func (set *DBSetter) parseOperator(segment string, i int) int {
|
|
var buffer string
|
|
for ; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
if isOpByte(ch) {
|
|
buffer += string(ch)
|
|
} else {
|
|
i--
|
|
set.Expr = append(set.Expr, DBToken{buffer, TokenOp})
|
|
return i
|
|
}
|
|
}
|
|
return i
|
|
}
|
|
|
|
func processSet(setstr string) (setter []DBSetter) {
|
|
if setstr == "" {
|
|
return setter
|
|
}
|
|
|
|
// First pass, splitting the string by commas while ignoring the innards of functions
|
|
var setset []string
|
|
var buffer string
|
|
var lastItem int
|
|
setstr += ","
|
|
for i := 0; i < len(setstr); i++ {
|
|
if setstr[i] == '(' {
|
|
i = skipFunctionCall(setstr, i-1)
|
|
setset = append(setset, setstr[lastItem:i+1])
|
|
buffer = ""
|
|
lastItem = i + 2
|
|
} else if setstr[i] == ',' && buffer != "" {
|
|
setset = append(setset, buffer)
|
|
buffer = ""
|
|
lastItem = i + 1
|
|
} else if (setstr[i] > 32) && setstr[i] != ',' && setstr[i] != ')' {
|
|
buffer += string(setstr[i])
|
|
}
|
|
}
|
|
|
|
// Second pass. Break this setitem into manageable chunks
|
|
for _, setitem := range setset {
|
|
halves := strings.Split(setitem, "=")
|
|
if len(halves) != 2 {
|
|
continue
|
|
}
|
|
tmpSetter := &DBSetter{Column: strings.TrimSpace(halves[0])}
|
|
segment := halves[1] + ")"
|
|
|
|
for i := 0; i < len(segment); i++ {
|
|
ch := segment[i]
|
|
switch {
|
|
case '0' <= ch && ch <= '9':
|
|
i = tmpSetter.parseNumber(segment, i)
|
|
case ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ch == '_':
|
|
i = tmpSetter.parseColumn(segment, i)
|
|
case ch == '\'':
|
|
i = tmpSetter.parseString(segment, i)
|
|
case isOpByte(ch):
|
|
i = tmpSetter.parseOperator(segment, i)
|
|
case ch == '?':
|
|
tmpSetter.Expr = append(tmpSetter.Expr, DBToken{"?", TokenSub})
|
|
}
|
|
}
|
|
setter = append(setter, *tmpSetter)
|
|
}
|
|
return setter
|
|
}
|
|
|
|
func processLimit(limitStr string) (limit DBLimit) {
|
|
halves := strings.Split(limitStr, ",")
|
|
if len(halves) == 2 {
|
|
limit.Offset = halves[0]
|
|
limit.MaxCount = halves[1]
|
|
} else {
|
|
limit.MaxCount = halves[0]
|
|
}
|
|
return limit
|
|
}
|
|
|
|
func isOpByte(ch byte) bool {
|
|
return ch == '<' || ch == '>' || ch == '=' || ch == '!' || ch == '*' || ch == '%' || ch == '+' || ch == '-' || ch == '/' || ch == '(' || ch == ')'
|
|
}
|
|
|
|
func isOpRune(ch rune) bool {
|
|
return ch == '<' || ch == '>' || ch == '=' || ch == '!' || ch == '*' || ch == '%' || ch == '+' || ch == '-' || ch == '/' || ch == '(' || ch == ')'
|
|
}
|
|
|
|
func processFields(fieldStr string) (fields []DBField) {
|
|
if fieldStr == "" {
|
|
return fields
|
|
}
|
|
var buffer string
|
|
var lastItem int
|
|
fieldStr += ","
|
|
for i := 0; i < len(fieldStr); i++ {
|
|
ch := fieldStr[i]
|
|
if ch == '(' {
|
|
i = skipFunctionCall(fieldStr, i-1)
|
|
fields = append(fields, DBField{Name: fieldStr[lastItem : i+1], Type: getIdentifierType(fieldStr[lastItem : i+1])})
|
|
buffer = ""
|
|
lastItem = i + 2
|
|
} else if ch == ',' && buffer != "" {
|
|
fields = append(fields, DBField{Name: buffer, Type: getIdentifierType(buffer)})
|
|
buffer = ""
|
|
lastItem = i + 1
|
|
} else if (ch >= 32) && ch != ',' && ch != ')' {
|
|
buffer += string(ch)
|
|
}
|
|
}
|
|
return fields
|
|
}
|
|
|
|
func getIdentifierType(iden string) string {
|
|
if ('a' <= iden[0] && iden[0] <= 'z') || ('A' <= iden[0] && iden[0] <= 'Z') {
|
|
if iden[len(iden)-1] == ')' {
|
|
return "function"
|
|
}
|
|
return "column"
|
|
}
|
|
if iden[0] == '\'' || iden[0] == '"' {
|
|
return "string"
|
|
}
|
|
return "literal"
|
|
}
|
|
|
|
func getIdentifier(seg string, startOffset int) (out string, i int) {
|
|
seg = strings.TrimSpace(seg)
|
|
seg += " " // Avoid overflow bugs with slicing
|
|
for i = startOffset; i < len(seg); i++ {
|
|
ch := seg[i]
|
|
if ch == '(' {
|
|
i = skipFunctionCall(seg, i)
|
|
return strings.TrimSpace(seg[startOffset:i]), (i - 1)
|
|
}
|
|
if (ch == ' ' || isOpByte(ch)) && i != startOffset {
|
|
return strings.TrimSpace(seg[startOffset:i]), (i - 1)
|
|
}
|
|
}
|
|
return strings.TrimSpace(seg[startOffset:]), (i - 1)
|
|
}
|
|
|
|
func getOperator(seg string, startOffset int) (out string, i int) {
|
|
seg = strings.TrimSpace(seg)
|
|
seg += " " // Avoid overflow bugs with slicing
|
|
for i = startOffset; i < len(seg); i++ {
|
|
if !isOpByte(seg[i]) && i != startOffset {
|
|
return strings.TrimSpace(seg[startOffset:i]), (i - 1)
|
|
}
|
|
}
|
|
return strings.TrimSpace(seg[startOffset:]), (i - 1)
|
|
}
|
|
|
|
func skipFunctionCall(data string, index int) int {
|
|
var braceCount int
|
|
for ; index < len(data); index++ {
|
|
char := data[index]
|
|
if char == '(' {
|
|
braceCount++
|
|
} else if char == ')' {
|
|
braceCount--
|
|
if braceCount == 0 {
|
|
return index
|
|
}
|
|
}
|
|
}
|
|
return index
|
|
}
|
|
|
|
func writeFile(name string, content string) (err error) {
|
|
f, err := os.Create(name)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
_, err = f.WriteString(content)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = f.Sync()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return f.Close()
|
|
}
|