craban/vendor/github.com/Masterminds/squirrel/README.md
2021-09-11 21:38:38 +02:00

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[![Project Status: Inactive The project has reached a stable, usable state but is no longer being actively developed; support/maintenance will be provided as time allows.](https://www.repostatus.org/badges/latest/inactive.svg)](https://www.repostatus.org/#inactive)
### Squirrel is "complete".
Bug fixes will still be merged (slowly). Bug reports are welcome, but I will not necessarily respond to them. If another fork (or substantially similar project) actively improves on what Squirrel does, let me know and I may link to it here.
# Squirrel - fluent SQL generator for Go
```go
import "github.com/Masterminds/squirrel"
```
[![GoDoc](https://godoc.org/github.com/Masterminds/squirrel?status.png)](https://godoc.org/github.com/Masterminds/squirrel)
[![Build Status](https://api.travis-ci.org/Masterminds/squirrel.svg?branch=master)](https://travis-ci.org/Masterminds/squirrel)
**Squirrel is not an ORM.** For an application of Squirrel, check out
[structable, a table-struct mapper](https://github.com/Masterminds/structable)
Squirrel helps you build SQL queries from composable parts:
```go
import sq "github.com/Masterminds/squirrel"
users := sq.Select("*").From("users").Join("emails USING (email_id)")
active := users.Where(sq.Eq{"deleted_at": nil})
sql, args, err := active.ToSql()
sql == "SELECT * FROM users JOIN emails USING (email_id) WHERE deleted_at IS NULL"
```
```go
sql, args, err := sq.
Insert("users").Columns("name", "age").
Values("moe", 13).Values("larry", sq.Expr("? + 5", 12)).
ToSql()
sql == "INSERT INTO users (name,age) VALUES (?,?),(?,? + 5)"
```
Squirrel can also execute queries directly:
```go
stooges := users.Where(sq.Eq{"username": []string{"moe", "larry", "curly", "shemp"}})
three_stooges := stooges.Limit(3)
rows, err := three_stooges.RunWith(db).Query()
// Behaves like:
rows, err := db.Query("SELECT * FROM users WHERE username IN (?,?,?,?) LIMIT 3",
"moe", "larry", "curly", "shemp")
```
Squirrel makes conditional query building a breeze:
```go
if len(q) > 0 {
users = users.Where("name LIKE ?", fmt.Sprint("%", q, "%"))
}
```
Squirrel wants to make your life easier:
```go
// StmtCache caches Prepared Stmts for you
dbCache := sq.NewStmtCacher(db)
// StatementBuilder keeps your syntax neat
mydb := sq.StatementBuilder.RunWith(dbCache)
select_users := mydb.Select("*").From("users")
```
Squirrel loves PostgreSQL:
```go
psql := sq.StatementBuilder.PlaceholderFormat(sq.Dollar)
// You use question marks for placeholders...
sql, _, _ := psql.Select("*").From("elephants").Where("name IN (?,?)", "Dumbo", "Verna").ToSql()
/// ...squirrel replaces them using PlaceholderFormat.
sql == "SELECT * FROM elephants WHERE name IN ($1,$2)"
/// You can retrieve id ...
query := sq.Insert("nodes").
Columns("uuid", "type", "data").
Values(node.Uuid, node.Type, node.Data).
Suffix("RETURNING \"id\"").
RunWith(m.db).
PlaceholderFormat(sq.Dollar)
query.QueryRow().Scan(&node.id)
```
You can escape question marks by inserting two question marks:
```sql
SELECT * FROM nodes WHERE meta->'format' ??| array[?,?]
```
will generate with the Dollar Placeholder:
```sql
SELECT * FROM nodes WHERE meta->'format' ?| array[$1,$2]
```
## FAQ
* **How can I build an IN query on composite keys / tuples, e.g. `WHERE (col1, col2) IN ((1,2),(3,4))`? ([#104](https://github.com/Masterminds/squirrel/issues/104))**
Squirrel does not explicitly support tuples, but you can get the same effect with e.g.:
```go
sq.Or{
sq.Eq{"col1": 1, "col2": 2},
sq.Eq{"col1": 3, "col2": 4}}
```
```sql
WHERE (col1 = 1 AND col2 = 2) OR (col1 = 3 AND col2 = 4)
```
(which should produce the same query plan as the tuple version)
* **Why doesn't `Eq{"mynumber": []uint8{1,2,3}}` turn into an `IN` query? ([#114](https://github.com/Masterminds/squirrel/issues/114))**
Values of type `[]byte` are handled specially by `database/sql`. In Go, [`byte` is just an alias of `uint8`](https://golang.org/pkg/builtin/#byte), so there is no way to distinguish `[]uint8` from `[]byte`.
* **Some features are poorly documented!**
This isn't a frequent complaints section!
* **Some features are poorly documented?**
Yes. The tests should be considered a part of the documentation; take a look at those for ideas on how to express more complex queries.
## License
Squirrel is released under the
[MIT License](http://www.opensource.org/licenses/MIT).