143 lines
4.3 KiB
Markdown
143 lines
4.3 KiB
Markdown
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[![Stability: Maintenance](https://masterminds.github.io/stability/maintenance.svg)](https://masterminds.github.io/stability/maintenance.html)
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### Squirrel is "complete".
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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.
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# Squirrel - fluent SQL generator for Go
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```go
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import "github.com/Masterminds/squirrel"
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```
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[![GoDoc](https://godoc.org/github.com/Masterminds/squirrel?status.png)](https://godoc.org/github.com/Masterminds/squirrel)
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[![Build Status](https://api.travis-ci.org/Masterminds/squirrel.svg?branch=master)](https://travis-ci.org/Masterminds/squirrel)
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**Squirrel is not an ORM.** For an application of Squirrel, check out
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[structable, a table-struct mapper](https://github.com/Masterminds/structable)
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Squirrel helps you build SQL queries from composable parts:
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```go
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import sq "github.com/Masterminds/squirrel"
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users := sq.Select("*").From("users").Join("emails USING (email_id)")
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active := users.Where(sq.Eq{"deleted_at": nil})
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sql, args, err := active.ToSql()
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sql == "SELECT * FROM users JOIN emails USING (email_id) WHERE deleted_at IS NULL"
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```
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```go
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sql, args, err := sq.
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Insert("users").Columns("name", "age").
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Values("moe", 13).Values("larry", sq.Expr("? + 5", 12)).
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ToSql()
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sql == "INSERT INTO users (name,age) VALUES (?,?),(?,? + 5)"
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```
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Squirrel can also execute queries directly:
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```go
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stooges := users.Where(sq.Eq{"username": []string{"moe", "larry", "curly", "shemp"}})
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three_stooges := stooges.Limit(3)
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rows, err := three_stooges.RunWith(db).Query()
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// Behaves like:
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rows, err := db.Query("SELECT * FROM users WHERE username IN (?,?,?,?) LIMIT 3",
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"moe", "larry", "curly", "shemp")
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```
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Squirrel makes conditional query building a breeze:
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```go
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if len(q) > 0 {
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users = users.Where("name LIKE ?", fmt.Sprint("%", q, "%"))
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}
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```
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Squirrel wants to make your life easier:
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```go
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// StmtCache caches Prepared Stmts for you
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dbCache := sq.NewStmtCache(db)
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// StatementBuilder keeps your syntax neat
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mydb := sq.StatementBuilder.RunWith(dbCache)
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select_users := mydb.Select("*").From("users")
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```
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Squirrel loves PostgreSQL:
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```go
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psql := sq.StatementBuilder.PlaceholderFormat(sq.Dollar)
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// You use question marks for placeholders...
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sql, _, _ := psql.Select("*").From("elephants").Where("name IN (?,?)", "Dumbo", "Verna").ToSql()
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/// ...squirrel replaces them using PlaceholderFormat.
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sql == "SELECT * FROM elephants WHERE name IN ($1,$2)"
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/// You can retrieve id ...
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query := sq.Insert("nodes").
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Columns("uuid", "type", "data").
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Values(node.Uuid, node.Type, node.Data).
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Suffix("RETURNING \"id\"").
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RunWith(m.db).
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PlaceholderFormat(sq.Dollar)
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query.QueryRow().Scan(&node.id)
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```
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You can escape question marks by inserting two question marks:
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```sql
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SELECT * FROM nodes WHERE meta->'format' ??| array[?,?]
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```
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will generate with the Dollar Placeholder:
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```sql
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SELECT * FROM nodes WHERE meta->'format' ?| array[$1,$2]
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```
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## FAQ
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* **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))**
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Squirrel does not explicitly support tuples, but you can get the same effect with e.g.:
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```go
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sq.Or{
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sq.Eq{"col1": 1, "col2": 2},
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sq.Eq{"col1": 3, "col2": 4}}
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```
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```sql
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WHERE (col1 = 1 AND col2 = 2) OR (col1 = 3 AND col2 = 4)
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```
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(which should produce the same query plan as the tuple version)
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* **Why doesn't `Eq{"mynumber": []uint8{1,2,3}}` turn into an `IN` query? ([#114](https://github.com/Masterminds/squirrel/issues/114))**
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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`.
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* **Some features are poorly documented!**
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This isn't a frequent complaints section!
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* **Some features are poorly documented?**
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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.
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## License
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Squirrel is released under the
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[MIT License](http://www.opensource.org/licenses/MIT).
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