mirror of
https://github.com/neilotoole/sq.git
synced 2024-12-22 23:51:44 +03:00
69 lines
2.1 KiB
Go
69 lines
2.1 KiB
Go
// Package dialect contains functionality for SQL dialects.
|
|
package dialect
|
|
|
|
import (
|
|
"github.com/neilotoole/sq/libsq/core/jointype"
|
|
"github.com/neilotoole/sq/libsq/source/drivertype"
|
|
)
|
|
|
|
// Dialect holds driver-specific SQL dialect values and functions.
|
|
type Dialect struct {
|
|
// Type is the dialect's driver type.
|
|
Type drivertype.Type `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
|
|
|
|
// Enquote is a function that quotes and escapes an
|
|
// identifier (such as a table or column name). Typically the func
|
|
// uses the double-quote rune (although MySQL uses backtick).
|
|
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 overridden SLQ operator (e.g. "==" or "!=") to
|
|
// its SQL rendering.
|
|
Ops map[string]string
|
|
|
|
// Joins is the set of JOIN types (e.g. "RIGHT JOIN") that
|
|
// the dialect supports. Not all drivers support each join type. For
|
|
// example, MySQL doesn't support jointype.FullOuter.
|
|
Joins []jointype.Type
|
|
|
|
// Catalog indicates that the database supports the catalog concept,
|
|
// in addition to schema. For example, PostgreSQL supports catalog
|
|
// and schema (sakila.public.actor), whereas MySQL only supports schema
|
|
// (sakila.actor).
|
|
Catalog bool
|
|
}
|
|
|
|
// 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
|
|
}
|