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mirror of https://github.com/uptrace/go-clickhouse.git synced 2025-06-08 23:26:11 +02:00
go-clickhouse/ch/query_select.go
2022-11-01 15:22:10 +02:00

626 lines
13 KiB
Go

package ch
import (
"context"
"database/sql"
"errors"
"strconv"
"strings"
"sync"
"github.com/uptrace/go-clickhouse/ch/chschema"
"github.com/uptrace/go-clickhouse/ch/internal"
)
type SelectQuery struct {
whereBaseQuery
sample chschema.QueryWithArgs
distinctOn []chschema.QueryWithArgs
joins []joinQuery
group []chschema.QueryWithArgs
having []chschema.QueryWithArgs
order []chschema.QueryWithArgs
limit int
offset int
final bool
}
var _ Query = (*SelectQuery)(nil)
func NewSelectQuery(db *DB) *SelectQuery {
return &SelectQuery{
whereBaseQuery: whereBaseQuery{
baseQuery: baseQuery{
db: db,
},
},
}
}
func (q *SelectQuery) Operation() string {
return "SELECT"
}
func (q *SelectQuery) Model(model any) *SelectQuery {
q.setTableModel(model)
return q
}
func (q *SelectQuery) Err(err error) *SelectQuery {
q.setErr(err)
return q
}
func (q *SelectQuery) WithQuery(fn func(*SelectQuery) *SelectQuery) *SelectQuery {
return fn(q)
}
func (q *SelectQuery) WithAlias(name, query string, args ...any) *SelectQuery {
for i := range q.with {
with := &q.with[i]
if with.name == name {
with.query = chschema.SafeQuery(query, args)
return q
}
}
q.with = append(q.with, withQuery{
name: name,
query: chschema.SafeQuery(query, args),
})
return q
}
func (q *SelectQuery) With(name string, subq chschema.QueryAppender) *SelectQuery {
q.with = append(q.with, withQuery{
name: name,
query: subq,
cte: true,
})
return q
}
func (q *SelectQuery) Distinct() *SelectQuery {
q.distinctOn = make([]chschema.QueryWithArgs, 0)
return q
}
func (q *SelectQuery) DistinctOn(query string, args ...any) *SelectQuery {
q.distinctOn = append(q.distinctOn, chschema.SafeQuery(query, args))
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) Table(tables ...string) *SelectQuery {
for _, table := range tables {
q.addTable(chschema.UnsafeIdent(table))
}
return q
}
func (q *SelectQuery) TableExpr(query string, args ...any) *SelectQuery {
q.addTable(chschema.SafeQuery(query, args))
return q
}
func (q *SelectQuery) ModelTableExpr(query string, args ...any) *SelectQuery {
q.modelTableName = chschema.SafeQuery(query, args)
return q
}
func (q *SelectQuery) Sample(query string, args ...any) *SelectQuery {
q.sample = chschema.SafeQuery(query, args)
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) Column(columns ...string) *SelectQuery {
for _, column := range columns {
q.addColumn(chschema.UnsafeIdent(column))
}
return q
}
func (q *SelectQuery) ColumnExpr(query string, args ...any) *SelectQuery {
q.addColumn(chschema.SafeQuery(query, args))
return q
}
func (q *SelectQuery) ExcludeColumn(columns ...string) *SelectQuery {
q.excludeColumn(columns)
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) Join(join string, args ...any) *SelectQuery {
q.joins = append(q.joins, joinQuery{
join: chschema.SafeQuery(join, args),
})
return q
}
func (q *SelectQuery) JoinOn(cond string, args ...any) *SelectQuery {
return q.joinOn(cond, args, " AND ")
}
func (q *SelectQuery) JoinOnOr(cond string, args ...any) *SelectQuery {
return q.joinOn(cond, args, " OR ")
}
func (q *SelectQuery) joinOn(cond string, args []any, sep string) *SelectQuery {
if len(q.joins) == 0 {
q.err = errors.New("ch: query has no joins")
return q
}
j := &q.joins[len(q.joins)-1]
j.on = append(j.on, chschema.SafeQueryWithSep(cond, args, sep))
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) Where(query string, args ...any) *SelectQuery {
q.addWhere(chschema.SafeQueryWithSep(query, args, " AND "))
return q
}
func (q *SelectQuery) WhereOr(query string, args ...any) *SelectQuery {
q.addWhere(chschema.SafeQueryWithSep(query, args, " OR "))
return q
}
func (q *SelectQuery) WhereGroup(sep string, fn func(*SelectQuery) *SelectQuery) *SelectQuery {
saved := q.where
q.where = nil
q = fn(q)
where := q.where
q.where = saved
q.addWhereGroup(sep, where)
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) Group(columns ...string) *SelectQuery {
for _, column := range columns {
q.group = append(q.group, chschema.UnsafeIdent(column))
}
return q
}
func (q *SelectQuery) GroupExpr(group string, args ...any) *SelectQuery {
q.group = append(q.group, chschema.SafeQuery(group, args))
return q
}
func (q *SelectQuery) Having(having string, args ...any) *SelectQuery {
q.having = append(q.having, chschema.SafeQuery(having, args))
return q
}
func (q *SelectQuery) Order(orders ...string) *SelectQuery {
for _, order := range orders {
if order == "" {
continue
}
index := strings.IndexByte(order, ' ')
if index == -1 {
q.order = append(q.order, chschema.UnsafeIdent(order))
continue
}
field := order[:index]
sort := order[index+1:]
switch strings.ToUpper(sort) {
case "ASC", "DESC", "ASC NULLS FIRST", "DESC NULLS FIRST",
"ASC NULLS LAST", "DESC NULLS LAST":
q.order = append(q.order, chschema.SafeQuery("? ?", []any{
Ident(field),
Safe(sort),
}))
default:
q.order = append(q.order, chschema.UnsafeIdent(order))
}
}
return q
}
// Order adds sort order to the Query.
func (q *SelectQuery) OrderExpr(order string, args ...any) *SelectQuery {
q.order = append(q.order, chschema.SafeQuery(order, args))
return q
}
func (q *SelectQuery) Limit(limit int) *SelectQuery {
q.limit = limit
return q
}
func (q *SelectQuery) Offset(offset int) *SelectQuery {
q.offset = offset
return q
}
func (q *SelectQuery) Final() *SelectQuery {
q.final = true
return q
}
func (q *SelectQuery) Setting(query string, args ...any) *SelectQuery {
q.settings = append(q.settings, chschema.SafeQuery(query, args))
return q
}
//------------------------------------------------------------------------------
func (q *SelectQuery) String() string {
b, err := q.AppendQuery(q.db.fmter, nil)
if err != nil {
return err.Error()
}
return internal.String(b)
}
func (q *SelectQuery) AppendQuery(fmter chschema.Formatter, b []byte) (_ []byte, err error) {
return q.appendQuery(formatterWithModel(fmter, q), b, false)
}
func (q *SelectQuery) appendQuery(
fmter chschema.Formatter, b []byte, count bool,
) (_ []byte, err error) {
if q.err != nil {
return nil, q.err
}
cteCount := count && (len(q.group) > 0 || len(q.distinctOn) > 0)
if cteCount {
b = append(b, `WITH "_count_wrapper" AS (`...)
}
if len(q.with) > 0 {
b, err = q.appendWith(fmter, b)
if err != nil {
return nil, err
}
}
b = append(b, "SELECT "...)
if len(q.distinctOn) > 0 {
b = append(b, "DISTINCT ON ("...)
for i, app := range q.distinctOn {
if i > 0 {
b = append(b, ", "...)
}
b, err = app.AppendQuery(fmter, b)
}
b = append(b, ") "...)
} else if q.distinctOn != nil {
b = append(b, "DISTINCT "...)
}
if count && !cteCount {
b = append(b, "count()"...)
} else {
b, err = q.appendColumns(fmter, b)
if err != nil {
return nil, err
}
}
if q.hasTables() {
b = append(b, " FROM "...)
b, err = q.appendTablesWithAlias(fmter, b)
if err != nil {
return nil, err
}
}
if !q.sample.IsZero() {
b = append(b, " SAMPLE "...)
b, err = q.sample.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
}
for _, j := range q.joins {
b = append(b, ' ')
b, err = j.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
}
b, err = q.appendWhere(fmter, b)
if err != nil {
return nil, err
}
if len(q.group) > 0 {
b = append(b, " GROUP BY "...)
for i, f := range q.group {
if i > 0 {
b = append(b, ", "...)
}
b, err = f.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
}
}
if len(q.having) > 0 {
b = append(b, " HAVING "...)
for i, f := range q.having {
if i > 0 {
b = append(b, " AND "...)
}
b = append(b, '(')
b, err = f.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
b = append(b, ')')
}
}
if !count {
if len(q.order) > 0 {
b = append(b, " ORDER BY "...)
for i, f := range q.order {
if i > 0 {
b = append(b, ", "...)
}
b, err = f.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
}
}
if q.limit > 0 {
b = append(b, " LIMIT "...)
b = strconv.AppendInt(b, int64(q.limit), 10)
}
if q.offset > 0 {
b = append(b, " OFFSET "...)
b = strconv.AppendInt(b, int64(q.offset), 10)
}
if q.final {
b = append(b, " FINAL"...)
}
} else if cteCount {
b = append(b, `) SELECT `...)
b = append(b, "count()"...)
b = append(b, ` FROM "_count_wrapper"`...)
}
b, err = q.appendSettings(fmter, b)
if err != nil {
return nil, err
}
return b, nil
}
func (q *SelectQuery) appendWith(fmter chschema.Formatter, b []byte) (_ []byte, err error) {
b = append(b, "WITH "...)
for i, with := range q.with {
if i > 0 {
b = append(b, ", "...)
}
if with.cte {
b = chschema.AppendIdent(b, with.name)
b = append(b, " AS "...)
b = append(b, "("...)
}
b, err = with.query.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
if with.cte {
b = append(b, ")"...)
} else {
b = append(b, " AS "...)
b = chschema.AppendIdent(b, with.name)
}
}
b = append(b, ' ')
return b, nil
}
func (q *SelectQuery) appendColumns(fmter chschema.Formatter, b []byte) (_ []byte, err error) {
switch {
case q.columns != nil:
for i, f := range q.columns {
if i > 0 {
b = append(b, ", "...)
}
b, err = f.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
}
case q.table != nil:
b = appendTableColumns(b, q.table.CHAlias, q.table.Fields)
default:
b = append(b, '*')
}
return b, nil
}
func appendTableColumns(b []byte, table chschema.Safe, fields []*chschema.Field) []byte {
for i, f := range fields {
if i > 0 {
b = append(b, ", "...)
}
if len(table) > 0 {
b = append(b, table...)
b = append(b, '.')
}
b = append(b, f.Column...)
}
return b
}
func (q *SelectQuery) Scan(ctx context.Context, values ...any) error {
return q.scan(ctx, false, values...)
}
func (q *SelectQuery) ScanColumns(ctx context.Context, values ...any) error {
return q.scan(ctx, true, values...)
}
func (q *SelectQuery) scan(ctx context.Context, columnar bool, values ...any) error {
if q.err != nil {
return q.err
}
model, err := q.newModel(values...)
if err != nil {
return err
}
if columnar {
model.(interface{ SetColumnar(bool) }).SetColumnar(true)
}
queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
if err != nil {
return err
}
query := internal.String(queryBytes)
ctx, evt := q.db.beforeQuery(ctx, q, query, nil, model)
res, err := q.query(ctx, model, query)
q.db.afterQuery(ctx, evt, res, err)
if err != nil {
return err
}
if !columnar && useQueryRowModel(model) {
if res.affected == 0 {
return sql.ErrNoRows
}
}
return nil
}
func useQueryRowModel(model Model) bool {
if v, ok := model.(interface{ UseQueryRow() bool }); ok {
return v.UseQueryRow()
}
return false
}
// Count returns number of rows matching the query using count aggregate function.
func (q *SelectQuery) Count(ctx context.Context) (int, error) {
if q.err != nil {
return 0, q.err
}
queryBytes, err := q.appendQuery(q.db.fmter, nil, true)
if err != nil {
return 0, err
}
query := internal.String(queryBytes)
var count uint
err = q.db.QueryRowContext(ctx, query).Scan(&count)
return int(count), err
}
// SelectAndCount runs Select and Count in two goroutines,
// waits for them to finish and returns the result. If query limit is -1
// it does not select any data and only counts the results.
func (q *SelectQuery) ScanAndCount(
ctx context.Context, values ...any,
) (count int, firstErr error) {
if q.err != nil {
return 0, q.err
}
var wg sync.WaitGroup
var mu sync.Mutex
if q.limit >= 0 {
wg.Add(1)
go func() {
defer wg.Done()
err := q.Scan(ctx, values...)
if err != nil {
mu.Lock()
if firstErr == nil {
firstErr = err
}
mu.Unlock()
}
}()
}
wg.Add(1)
go func() {
defer wg.Done()
var err error
count, err = q.Count(ctx)
if err != nil {
mu.Lock()
if firstErr == nil {
firstErr = err
}
mu.Unlock()
}
}()
wg.Wait()
return count, firstErr
}
//------------------------------------------------------------------------------
type joinQuery struct {
join chschema.QueryWithArgs
on []chschema.QueryWithSep
}
func (j *joinQuery) AppendQuery(fmter chschema.Formatter, b []byte) (_ []byte, err error) {
b = append(b, ' ')
b, err = j.join.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
if len(j.on) > 0 {
b = append(b, " ON "...)
for i, on := range j.on {
if i > 0 {
b = append(b, on.Sep...)
}
b = append(b, '(')
b, err = on.AppendQuery(fmter, b)
if err != nil {
return nil, err
}
b = append(b, ')')
}
}
return b, nil
}