sq/libsq/driver/dialect/dialect.go
Neil O'Toole 81f631e135
Refactoring ()
* Renamed source.Type to source.DriverType for clarity

* More renaming wrt source.DriverType

* Renamed output.Formatting to output.Printing
2023-04-21 21:36:32 -06:00

62 lines
1.8 KiB
Go

// Package dialect contains functionality for SQL dialects.
package dialect
import "github.com/neilotoole/sq/libsq/source"
// Dialect holds driver-specific SQL dialect values and functions.
type Dialect struct {
// Type is the dialect's driver type.
Type source.DriverType `json:"type"`
// Placeholders returns a string a SQL placeholders string.
// For example "(?, ?, ?)" or "($1, $2, $3), ($4, $5, $6)".
Placeholders func(numCols, numRows int) string
// IdentQuote is the identifier quote rune. Most often this is
// double-quote, e.g. SELECT * FROM "my_table", but can be other
// values such as backtick, e.g. SELECT * FROM `my_table`.
//
// Arguably, this field should be deprecated. There's probably
// no reason not to always use Enquote.
IdentQuote rune `json:"quote"`
// Enquote is a function that quotes and escapes an
// identifier (such as a table or column name).
Enquote func(string) string
// IntBool is true if BOOLEAN is handled as an INT by the DB driver.
IntBool bool `json:"int_bool"`
// MaxBatchValues is the maximum number of values in a batch insert.
MaxBatchValues int
// Ops is a map of SLQ operator (e.g. "==" or "!=") to
// its default SQL rendering.
Ops map[string]string
}
// String returns a log/debug-friendly representation.
func (d Dialect) String() string {
return d.Type.String()
}
// defaultOps is a map of SLQ operator (e.g. "==" or "!=") to
// its default SQL rendering.
var defaultOps = map[string]string{
`==`: `=`,
`&&`: `AND`,
`||`: `OR`,
`!=`: `!=`,
}
// DefaultOps returns a default map of SLQ operator (e.g. "==" or "!=") to
// its SQL rendering. The returned map is a copy and can be safely
// modified by the caller.
func DefaultOps() map[string]string {
ops := make(map[string]string, len(defaultOps))
for k, v := range defaultOps {
ops[k] = v
}
return ops
}