-
Notifications
You must be signed in to change notification settings - Fork 1
/
funceval.go
564 lines (490 loc) · 12.5 KB
/
funceval.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
/*
* MinIO Cloud Storage, (C) 2019 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package sql
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
)
// FuncName - SQL function name.
type FuncName string
// SQL Function name constants
const (
// Conditionals
sqlFnCoalesce FuncName = "COALESCE"
sqlFnNullIf FuncName = "NULLIF"
// Conversion
sqlFnCast FuncName = "CAST"
// Date and time
sqlFnDateAdd FuncName = "DATE_ADD"
sqlFnDateDiff FuncName = "DATE_DIFF"
sqlFnExtract FuncName = "EXTRACT"
sqlFnToString FuncName = "TO_STRING"
sqlFnToTimestamp FuncName = "TO_TIMESTAMP"
sqlFnUTCNow FuncName = "UTCNOW"
// String
sqlFnCharLength FuncName = "CHAR_LENGTH"
sqlFnCharacterLength FuncName = "CHARACTER_LENGTH"
sqlFnLower FuncName = "LOWER"
sqlFnSubstring FuncName = "SUBSTRING"
sqlFnTrim FuncName = "TRIM"
sqlFnUpper FuncName = "UPPER"
)
var (
errUnimplementedCast = errors.New("This cast not yet implemented")
errNonStringTrimArg = errors.New("TRIM() received a non-string argument")
errNonTimestampArg = errors.New("Expected a timestamp argument")
)
func (e *FuncExpr) getFunctionName() FuncName {
switch {
case e.SFunc != nil:
return FuncName(strings.ToUpper(e.SFunc.FunctionName))
case e.Count != nil:
return FuncName(aggFnCount)
case e.Cast != nil:
return sqlFnCast
case e.Substring != nil:
return sqlFnSubstring
case e.Extract != nil:
return sqlFnExtract
case e.Trim != nil:
return sqlFnTrim
case e.DateAdd != nil:
return sqlFnDateAdd
case e.DateDiff != nil:
return sqlFnDateDiff
default:
return ""
}
}
// evalSQLFnNode assumes that the FuncExpr is not an aggregation
// function.
func (e *FuncExpr) evalSQLFnNode(r Record) (res *Value, err error) {
// Handle functions that have phrase arguments
switch e.getFunctionName() {
case sqlFnCast:
expr := e.Cast.Expr
res, err = expr.castTo(r, strings.ToUpper(e.Cast.CastType))
return
case sqlFnSubstring:
return handleSQLSubstring(r, e.Substring)
case sqlFnExtract:
return handleSQLExtract(r, e.Extract)
case sqlFnTrim:
return handleSQLTrim(r, e.Trim)
case sqlFnDateAdd:
return handleDateAdd(r, e.DateAdd)
case sqlFnDateDiff:
return handleDateDiff(r, e.DateDiff)
}
// For all simple argument functions, we evaluate the arguments here
argVals := make([]*Value, len(e.SFunc.ArgsList))
for i, arg := range e.SFunc.ArgsList {
argVals[i], err = arg.evalNode(r)
if err != nil {
return nil, err
}
}
switch e.getFunctionName() {
case sqlFnCoalesce:
return coalesce(argVals)
case sqlFnNullIf:
return nullif(argVals[0], argVals[1])
case sqlFnCharLength, sqlFnCharacterLength:
return charlen(argVals[0])
case sqlFnLower:
return lowerCase(argVals[0])
case sqlFnUpper:
return upperCase(argVals[0])
case sqlFnUTCNow:
return handleUTCNow()
case sqlFnToString, sqlFnToTimestamp:
// TODO: implement
fallthrough
default:
return nil, errNotImplemented
}
}
func coalesce(args []*Value) (res *Value, err error) {
for _, arg := range args {
if arg.IsNull() {
continue
}
return arg, nil
}
return FromNull(), nil
}
func nullif(v1, v2 *Value) (res *Value, err error) {
// Handle Null cases
if v1.IsNull() || v2.IsNull() {
return v1, nil
}
err = inferTypesForCmp(v1, v2)
if err != nil {
return nil, err
}
atleastOneNumeric := v1.isNumeric() || v2.isNumeric()
bothNumeric := v1.isNumeric() && v2.isNumeric()
if atleastOneNumeric || !bothNumeric {
return v1, nil
}
if v1.SameTypeAs(*v2) {
return v1, nil
}
cmpResult, cmpErr := v1.compareOp(opEq, v2)
if cmpErr != nil {
return nil, cmpErr
}
if cmpResult {
return FromNull(), nil
}
return v1, nil
}
func charlen(v *Value) (*Value, error) {
inferTypeAsString(v)
s, ok := v.ToString()
if !ok {
err := fmt.Errorf("%s/%s expects a string argument", sqlFnCharLength, sqlFnCharacterLength)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
return FromInt(int64(len([]rune(s)))), nil
}
func lowerCase(v *Value) (*Value, error) {
inferTypeAsString(v)
s, ok := v.ToString()
if !ok {
err := fmt.Errorf("%s expects a string argument", sqlFnLower)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
return FromString(strings.ToLower(s)), nil
}
func upperCase(v *Value) (*Value, error) {
inferTypeAsString(v)
s, ok := v.ToString()
if !ok {
err := fmt.Errorf("%s expects a string argument", sqlFnUpper)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
return FromString(strings.ToUpper(s)), nil
}
func handleDateAdd(r Record, d *DateAddFunc) (*Value, error) {
q, err := d.Quantity.evalNode(r)
if err != nil {
return nil, err
}
inferTypeForArithOp(q)
qty, ok := q.ToFloat()
if !ok {
return nil, fmt.Errorf("QUANTITY must be a numeric argument to %s()", sqlFnDateAdd)
}
ts, err := d.Timestamp.evalNode(r)
if err != nil {
return nil, err
}
if err = inferTypeAsTimestamp(ts); err != nil {
return nil, err
}
t, ok := ts.ToTimestamp()
if !ok {
return nil, fmt.Errorf("%s() expects a timestamp argument", sqlFnDateAdd)
}
return dateAdd(strings.ToUpper(d.DatePart), qty, t)
}
func handleDateDiff(r Record, d *DateDiffFunc) (*Value, error) {
tval1, err := d.Timestamp1.evalNode(r)
if err != nil {
return nil, err
}
if err = inferTypeAsTimestamp(tval1); err != nil {
return nil, err
}
ts1, ok := tval1.ToTimestamp()
if !ok {
return nil, fmt.Errorf("%s() expects two timestamp arguments", sqlFnDateDiff)
}
tval2, err := d.Timestamp2.evalNode(r)
if err != nil {
return nil, err
}
if err = inferTypeAsTimestamp(tval2); err != nil {
return nil, err
}
ts2, ok := tval2.ToTimestamp()
if !ok {
return nil, fmt.Errorf("%s() expects two timestamp arguments", sqlFnDateDiff)
}
return dateDiff(strings.ToUpper(d.DatePart), ts1, ts2)
}
func handleUTCNow() (*Value, error) {
return FromTimestamp(time.Now().UTC()), nil
}
func handleSQLSubstring(r Record, e *SubstringFunc) (val *Value, err error) {
// Both forms `SUBSTRING('abc' FROM 2 FOR 1)` and
// SUBSTRING('abc', 2, 1) are supported.
// Evaluate the string argument
v1, err := e.Expr.evalNode(r)
if err != nil {
return nil, err
}
inferTypeAsString(v1)
s, ok := v1.ToString()
if !ok {
err := fmt.Errorf("Incorrect argument type passed to %s", sqlFnSubstring)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
// Assemble other arguments
arg2, arg3 := e.From, e.For
// Check if the second form of substring is being used
if e.From == nil {
arg2, arg3 = e.Arg2, e.Arg3
}
// Evaluate the FROM argument
v2, err := arg2.evalNode(r)
if err != nil {
return nil, err
}
inferTypeForArithOp(v2)
startIdx, ok := v2.ToInt()
if !ok {
err := fmt.Errorf("Incorrect type for start index argument in %s", sqlFnSubstring)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
length := -1
// Evaluate the optional FOR argument
if arg3 != nil {
v3, err := arg3.evalNode(r)
if err != nil {
return nil, err
}
inferTypeForArithOp(v3)
lenInt, ok := v3.ToInt()
if !ok {
err := fmt.Errorf("Incorrect type for length argument in %s", sqlFnSubstring)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
length = int(lenInt)
if length < 0 {
err := fmt.Errorf("Negative length argument in %s", sqlFnSubstring)
return nil, errIncorrectSQLFunctionArgumentType(err)
}
}
res, err := evalSQLSubstring(s, int(startIdx), length)
return FromString(res), err
}
func handleSQLTrim(r Record, e *TrimFunc) (res *Value, err error) {
chars := ""
ok := false
if e.TrimChars != nil {
charsV, cerr := e.TrimChars.evalNode(r)
if cerr != nil {
return nil, cerr
}
inferTypeAsString(charsV)
chars, ok = charsV.ToString()
if !ok {
return nil, errNonStringTrimArg
}
}
fromV, ferr := e.TrimFrom.evalNode(r)
if ferr != nil {
return nil, ferr
}
inferTypeAsString(fromV)
from, ok := fromV.ToString()
if !ok {
return nil, errNonStringTrimArg
}
result, terr := evalSQLTrim(e.TrimWhere, chars, from)
if terr != nil {
return nil, terr
}
return FromString(result), nil
}
func handleSQLExtract(r Record, e *ExtractFunc) (res *Value, err error) {
timeVal, verr := e.From.evalNode(r)
if verr != nil {
return nil, verr
}
if err = inferTypeAsTimestamp(timeVal); err != nil {
return nil, err
}
t, ok := timeVal.ToTimestamp()
if !ok {
return nil, errNonTimestampArg
}
return extract(strings.ToUpper(e.Timeword), t)
}
func errUnsupportedCast(fromType, toType string) error {
return fmt.Errorf("Cannot cast from %v to %v", fromType, toType)
}
func errCastFailure(msg string) error {
return fmt.Errorf("Error casting: %s", msg)
}
// Allowed cast types
const (
castBool = "BOOL"
castInt = "INT"
castInteger = "INTEGER"
castString = "STRING"
castFloat = "FLOAT"
castDecimal = "DECIMAL"
castNumeric = "NUMERIC"
castTimestamp = "TIMESTAMP"
)
func (e *Expression) castTo(r Record, castType string) (res *Value, err error) {
v, err := e.evalNode(r)
if err != nil {
return nil, err
}
switch castType {
case castInt, castInteger:
i, err := intCast(v)
return FromInt(i), err
case castFloat:
f, err := floatCast(v)
return FromFloat(f), err
case castString:
s, err := stringCast(v)
return FromString(s), err
case castTimestamp:
t, err := timestampCast(v)
return FromTimestamp(t), err
case castBool:
b, err := boolCast(v)
return FromBool(b), err
case castDecimal, castNumeric:
fallthrough
default:
return nil, errUnimplementedCast
}
}
func intCast(v *Value) (int64, error) {
// This conversion truncates floating point numbers to
// integer.
strToInt := func(s string) (int64, bool) {
i, errI := strconv.ParseInt(s, 10, 64)
if errI == nil {
return i, true
}
f, errF := strconv.ParseFloat(s, 64)
if errF == nil {
return int64(f), true
}
return 0, false
}
switch x := v.value.(type) {
case float64:
// Truncate fractional part
return int64(x), nil
case int64:
return x, nil
case string:
// Parse as number, truncate floating point if
// needed.
res, ok := strToInt(x)
if !ok {
return 0, errCastFailure("could not parse as int")
}
return res, nil
case []byte:
// Parse as number, truncate floating point if
// needed.
res, ok := strToInt(string(x))
if !ok {
return 0, errCastFailure("could not parse as int")
}
return res, nil
default:
return 0, errUnsupportedCast(v.GetTypeString(), castInt)
}
}
func floatCast(v *Value) (float64, error) {
switch x := v.value.(type) {
case float64:
return x, nil
case int:
return float64(x), nil
case string:
f, err := strconv.ParseFloat(x, 64)
if err != nil {
return 0, errCastFailure("could not parse as float")
}
return f, nil
case []byte:
f, err := strconv.ParseFloat(string(x), 64)
if err != nil {
return 0, errCastFailure("could not parse as float")
}
return f, nil
default:
return 0, errUnsupportedCast(v.GetTypeString(), castFloat)
}
}
func stringCast(v *Value) (string, error) {
switch x := v.value.(type) {
case float64:
return fmt.Sprintf("%v", x), nil
case int64:
return fmt.Sprintf("%v", x), nil
case string:
return x, nil
case []byte:
return string(x), nil
case bool:
return fmt.Sprintf("%v", x), nil
case nil:
// FIXME: verify this case is correct
return "NULL", nil
}
// This does not happen
return "", errCastFailure(fmt.Sprintf("cannot cast %v to string type", v.GetTypeString()))
}
func timestampCast(v *Value) (t time.Time, _ error) {
switch x := v.value.(type) {
case string:
return parseSQLTimestamp(x)
case []byte:
return parseSQLTimestamp(string(x))
case time.Time:
return x, nil
default:
return t, errCastFailure(fmt.Sprintf("cannot cast %v to Timestamp type", v.GetTypeString()))
}
}
func boolCast(v *Value) (b bool, _ error) {
sToB := func(s string) (bool, error) {
switch s {
case "true":
return true, nil
case "false":
return false, nil
default:
return false, errCastFailure("cannot cast to Bool")
}
}
switch x := v.value.(type) {
case bool:
return x, nil
case string:
return sToB(strings.ToLower(x))
case []byte:
return sToB(strings.ToLower(string(x)))
default:
return false, errCastFailure("cannot cast %v to Bool")
}
}