Feature limit & benchmark tests & executable test moudle (#26)

* builder feature: union * complete README.md * UNION support *Builder only(it'll be better to reuse other components to avoid unnecessary problems) * add file head comment * modify file head comments * Uppercase: union -> UNION * enhance the function builder.From: allow query from a sub one * update related tests & update README.md * add one case in TestBuilder_From for simple from testing * fix bug & add test case * feature-limit & some tests add nested flag in builder that allow empty table name * Add file head comments Adjust references * Adjust references * Fix issue, adjust union function (will pass db dialect from base to its unions) * Fix unintended consequence in selectWriteTo * Update README.md * Fix issues & optimize codes * more test cases * optimize codes & update test cases * optimize codes & add benchmark test for limit query * update benchmark test for limit query * update benchmark test for limit query * Add benchmark test for basic queries & update some test cases * update benchmark test * update From(take out NestedFlag) & optimize Limit(use ROW_NUMBER() supported by mssql 2005 or later) & update test cases * add file head comments * update oracle limit * limit has been completed in the main & reconstruct feature UNION & update benchmark tests * remove redundant codes * add sql fiddler & test data sql scripts * update ci config * merge sql_fidder -> sql_test * rename func

Author: BetaCat0

.circleci/config.yml

@@ -24,6 +24,7 @@ jobs:
  # specify any bash command here prefixed with `run: `
  - run: go get -u github.com/golang/lint/golint
  - run: go get -u github.com/stretchr/testify/assert
+ - run: go get -u github.com/go-xorm/sqlfiddle
  - run: golint ./...
  - run: go test -v -race -coverprofile=coverage.txt -covermode=atomic
  - run: bash <(curl -s https://codecov.io/bash)

README.md

@@ -29,6 +29,13 @@ sql, args, err := Select("sub.id").From("sub", Select("c").From("table1").Where(
 sql, args, err = Select("sub.id").From("sub",
 Select("id").From("table1").Where(Eq{"a": 1}).
 Union("all", Select("id").From("table1").Where(Eq{"a": 2}))).Where(Eq{"b": 1}).ToSQL()
+// With order by
+sql, args, err = Select("a", "b", "c").From("table1").Where(Eq{"f1": "v1", "f2": "v2"}).
+OrderBy("a ASC").ToSQL()
+// With limit.
+// Be careful! You should set up specific dialect for builder before performing a query with LIMIT
+sql, args, err = Dialect(MYSQL).Select("a", "b", "c").From("table1").OrderBy("a ASC").
+Limit(5, 10).ToSQL()
 ```
 
 # Update

builder.go

@@ -15,6 +15,14 @@ const (
 unionType // union
 )
 
+const (
+POSTGRES = "postgres"
+SQLITE = "sqlite3"
+MYSQL = "mysql"
+MSSQL = "mssql"
+ORACLE = "oracle"
+)
+
 type join struct {
 joinType string
 joinTable string
@@ -26,20 +34,33 @@ type union struct {
 builder *Builder
 }
 
+type limit struct {
+limitN int
+offset int
+}
+
 // Builder describes a SQL statement
 type Builder struct {
 optype
-tableName string
-subQuery *Builder
-cond Cond
-selects []string
-joins []join
-unions []union
-inserts Eq
-updates []Eq
-orderBy string
-groupBy string
-having string
+dialect string
+tableName string
+subQuery *Builder
+cond Cond
+selects []string
+joins []join
+unions []union
+limitation *limit
+inserts Eq
+updates []Eq
+orderBy string
+groupBy string
+having string
+}
+
+// Dialect sets the db dialect of Builder.
+func Dialect(dialect string) *Builder {
+builder := &Builder{cond: NewCond(), dialect: dialect}
+return builder
 }
 
 // Where sets where SQL
@@ -88,23 +109,41 @@ func (b *Builder) Union(unionTp string, unionCond *Builder) *Builder {
 if b.optype != unionType {
 builder = &Builder{cond: NewCond()}
 builder.optype = unionType
+builder.dialect = b.dialect
+builder.selects = b.selects
 
 currentUnions := b.unions
 // erase sub unions (actually append to new Builder.unions)
 b.unions = nil
 
+for e := range currentUnions {
+currentUnions[e].builder.dialect = b.dialect
+}
+
 builder.unions = append(append(builder.unions, union{"", b}), currentUnions...)
 } else {
 builder = b
 }
 
 if unionCond != nil {
+unionCond.dialect = builder.dialect
 builder.unions = append(builder.unions, union{unionTp, unionCond})
 }
 
 return builder
 }
 
+// Limit sets limitN condition
+func (b *Builder) Limit(limitN int, offset ...int) *Builder {
+b.limitation = &limit{limitN: limitN}
+
+if len(offset) > 0 {
+b.limitation.offset = offset[0]
+}
+
+return b
+}
+
 // InnerJoin sets inner join
 func (b *Builder) InnerJoin(joinTable string, joinCond interface{}) *Builder {
 return b.Join("INNER", joinTable, joinCond)
@@ -205,12 +244,12 @@ func (b *Builder) ToSQL() (string, []interface{}, error) {
 return w.writer.String(), w.args, nil
 }
 
-// ToBindedSQL
-func (b *Builder) ToBindedSQL() (string, error) {
+// ToBoundSQL
+func (b *Builder) ToBoundSQL() (string, error) {
 w := NewWriter()
 if err := b.WriteTo(w); err != nil {
 return "", err
 }
 
-return ConvertToBindedSQL(w.writer.String(), w.args)
+return ConvertToBoundSQL(w.writer.String(), w.args)
 }