Squirrel

Import Squirrel into your Go project using the following path:

import "github.com/Masterminds/squirrel"

To improve performance and keep syntax clean, you can use NewStmtCache to cache prepared statements and StatementBuilder to create a reusable builder instance configured with a specific database and placeholder format.

// StmtCache caches Prepared Stmts for you
dbCache := sq.NewStmtCache(db)

// StatementBuilder keeps your syntax neat
mydb := sq.StatementBuilder.RunWith(dbCache)
select_users := mydb.Select("*").From("users")

Instead of just generating SQL strings, you can execute queries directly against a database connection by using the .RunWith(db) method. This allows you to call .Query(), .QueryRow(), or .Exec() directly on the builder.

// Assuming 'users' is a SelectBuilder and 'db' is a *sql.DB
stooges := users.Where(sq.Eq{"username": []string{"moe", "larry", "curly", "shemp"}})
three_stooges := stooges.Limit(3)

// Executes the query against the database
rows, err := three_stooges.RunWith(db).Query()

When using ExecContext, QueryContext, or QueryRowContext on a SelectBuilder, you may encounter the following errors:

• RunnerNotSet: You called an execution method without first calling .RunWith(runner).
• NoContextSupport: The runner provided to .RunWith() does not implement the required context interface (e.g., ExecerContext or QueryerContext).
• RunnerNotQueryRunner: Specifically for QueryRowContext, the runner was set but does not implement QueryRowerContext or QueryerContext.

When working with Squirrel builders, you may encounter these specific errors:

• RunnerNotSet: Returned by methods that require a Runner (set via .RunWith()) but none was provided.
• RunnerNotQueryRunner: Returned by QueryRow if the provided Runner does not implement the QueryRower interface.

When using context-aware methods on UpdateBuilder, you may encounter the following errors:

• RunnerNotSet: You forgot to call .RunWith(runner) on your builder.
• NoContextSupport: The runner provided to .RunWith() does not implement the required context interface (ExecerContext, QueryerContext, or QueryRowerContext).
• RunnerNotQueryRunner: You called QueryRowContext or ScanContext, but the runner only supports QueryerContext (standard Query) and not QueryRowerContext (standard QueryRow).

Use CaseBuilder to construct SQL CASE expressions. You can define an optional expression for the CASE value, multiple WHEN ... THEN ... clauses, and an optional ELSE clause.

Methods:

• what(expr interface{}) CaseBuilder: Sets the optional expression for the CASE [value] part.
• When(when interface{}, then interface{}) CaseBuilder: Adds a WHEN ... THEN ... clause. Both arguments can be raw values or other Sqlizer types.
• Else(expr interface{}) CaseBuilder: Sets the optional ELSE clause.
• ToSql() (string, []interface{}, error): Generates the SQL string and its associated arguments. Returns an error if no WHEN clauses are provided.
• MustSql() (string, []interface{}): Generates the SQL string and arguments, but panics if an error occurs (e.g., if no WHEN clauses exist).

The StmtCache type provides context-aware versions of standard database operations. When you call these methods, the cache automatically prepares the statement (if not already cached) and then executes it using the provided context.

Supported methods:

• ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
• QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
• QueryRowContext(ctx context.Context, query string, args ...interface{}) RowScanner
• PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)