Package sqlf focuses on building SQL queries by free combination of fragments.

The package exports only a few functions and methods, but improves a lot on the reusability and extensibility of SQL, which are the main challenges we encounter when writing SQL.

Fragment

Unlike any other sql builder or ORMs, Fragment is the only concept you need to learn.

Fragment is usually a part of a SQL query, which uses exactly the same syntax as database/sql, but provides the ability to combine them in any way.

import (
	"fmt"
	"github.com/qjebbs/go-sqlf/v2"
)
func Example_basic() {
	query, args, _ := sqlf.Ff(
		"SELECT * FROM foo WHERE #join('#fragment', ' AND ')", // join fragments
		sqlf.Fa("baz = $1", true),                             // `database/sql` style
		sqlf.Fa("bar BETWEEN ? AND ?", 1, 100),                // `database/sql` style
	).BuildQuery(syntax.Dollar)
	fmt.Println(query)
	fmt.Println(args)
	// Output:
	// SELECT * FROM foo WHERE baz = $1 AND bar BETWEEN $2 AND $3
	// [true 1 100]
}

Explanation:

• We pay attention only to the references inside a fragment, not between fragments.
• #join, #arg, #f, etc., are preprocessing functions, which will be explained later.
• See Example_deeperLook of example_test.go for what happend inside the *sqlf.Fragment.

Preprocessing Functions

name	description	example
f, fragment	fragments at index	#f1, #fragment1
join	Join the template with separator	#join('#f', ' AND ')
	Join from index 3 to end	#join('#f', ',', 3)
	Join from index 3 to 6	#join('#f', ',', 3, 6)
arg	arguments at index	#join('#arg', ',')

Note:

• #f1 is equivalent to #f(1), which is a special syntax to call preprocessing functions when an integer (usually an index) is the only argument.
• Expressions in the #join template are functions, not function calls.

See Example ContextWithFuncs of example_test.go for how to register custom preprocessing functions, and implementing global arguments/fragments.

QueryBuilder

*sqlb.QueryBuilder is a high-level abstraction of SQL queries for building complex queries, with *sqlf.Fragment as its underlying foundation.

See sqlb/example_test.go for examples.