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package sqlx
// Named Query Support
//
// * BindMap - bind query bindvars to map/struct args
// * NamedExec, NamedQuery - named query w/ struct or map
// * NamedStmt - a pre-compiled named query which is a prepared statement
//
// Internal Interfaces:
//
// * compileNamedQuery - rebind a named query, returning a query and list of names
// * bindArgs, bindMapArgs, bindAnyArgs - given a list of names, return an arglist
//
import (
"bytes"
"database/sql"
"errors"
"fmt"
"reflect"
"regexp"
"strconv"
"unicode"
"github.com/jmoiron/sqlx/reflectx"
)
// NamedStmt is a prepared statement that executes named queries. Prepare it
// how you would execute a NamedQuery, but pass in a struct or map when executing.
type NamedStmt struct {
Params []string
QueryString string
Stmt *Stmt
}
// Close closes the named statement.
func (n *NamedStmt) Close() error {
return n.Stmt.Close()
}
// Exec executes a named statement using the struct passed.
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) Exec(arg interface{}) (sql.Result, error) {
args, err := bindAnyArgs(n.Params, arg, n.Stmt.Mapper)
if err != nil {
return *new(sql.Result), err
}
return n.Stmt.Exec(args...)
}
// Query executes a named statement using the struct argument, returning rows.
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) Query(arg interface{}) (*sql.Rows, error) {
args, err := bindAnyArgs(n.Params, arg, n.Stmt.Mapper)
if err != nil {
return nil, err
}
return n.Stmt.Query(args...)
}
// QueryRow executes a named statement against the database. Because sqlx cannot
// create a *sql.Row with an error condition pre-set for binding errors, sqlx
// returns a *sqlx.Row instead.
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) QueryRow(arg interface{}) *Row {
args, err := bindAnyArgs(n.Params, arg, n.Stmt.Mapper)
if err != nil {
return &Row{err: err}
}
return n.Stmt.QueryRowx(args...)
}
// MustExec execs a NamedStmt, panicing on error
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) MustExec(arg interface{}) sql.Result {
res, err := n.Exec(arg)
if err != nil {
panic(err)
}
return res
}
// Queryx using this NamedStmt
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) Queryx(arg interface{}) (*Rows, error) {
r, err := n.Query(arg)
if err != nil {
return nil, err
}
return &Rows{Rows: r, Mapper: n.Stmt.Mapper, unsafe: isUnsafe(n)}, err
}
// QueryRowx this NamedStmt. Because of limitations with QueryRow, this is
// an alias for QueryRow.
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) QueryRowx(arg interface{}) *Row {
return n.QueryRow(arg)
}
// Select using this NamedStmt
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) Select(dest interface{}, arg interface{}) error {
rows, err := n.Queryx(arg)
if err != nil {
return err
}
// if something happens here, we want to make sure the rows are Closed
defer rows.Close()
return scanAll(rows, dest, false)
}
// Get using this NamedStmt
// Any named placeholder parameters are replaced with fields from arg.
func (n *NamedStmt) Get(dest interface{}, arg interface{}) error {
r := n.QueryRowx(arg)
return r.scanAny(dest, false)
}
// Unsafe creates an unsafe version of the NamedStmt
func (n *NamedStmt) Unsafe() *NamedStmt {
r := &NamedStmt{Params: n.Params, Stmt: n.Stmt, QueryString: n.QueryString}
r.Stmt.unsafe = true
return r
}
// A union interface of preparer and binder, required to be able to prepare
// named statements (as the bindtype must be determined).
type namedPreparer interface {
Preparer
binder
}
func prepareNamed(p namedPreparer, query string) (*NamedStmt, error) {
bindType := BindType(p.DriverName())
q, args, err := compileNamedQuery([]byte(query), bindType)
if err != nil {
return nil, err
}
stmt, err := Preparex(p, q)
if err != nil {
return nil, err
}
return &NamedStmt{
QueryString: q,
Params: args,
Stmt: stmt,
}, nil
}
func bindAnyArgs(names []string, arg interface{}, m *reflectx.Mapper) ([]interface{}, error) {
if maparg, ok := arg.(map[string]interface{}); ok {
return bindMapArgs(names, maparg)
}
return bindArgs(names, arg, m)
}
// private interface to generate a list of interfaces from a given struct
// type, given a list of names to pull out of the struct. Used by public
// BindStruct interface.
func bindArgs(names []string, arg interface{}, m *reflectx.Mapper) ([]interface{}, error) {
arglist := make([]interface{}, 0, len(names))
// grab the indirected value of arg
v := reflect.ValueOf(arg)
for v = reflect.ValueOf(arg); v.Kind() == reflect.Ptr; {
v = v.Elem()
}
err := m.TraversalsByNameFunc(v.Type(), names, func(i int, t []int) error {
if len(t) == 0 {
return fmt.Errorf("could not find name %s in %#v", names[i], arg)
}
val := reflectx.FieldByIndexesReadOnly(v, t)
arglist = append(arglist, val.Interface())
return nil
})
return arglist, err
}
// like bindArgs, but for maps.
func bindMapArgs(names []string, arg map[string]interface{}) ([]interface{}, error) {
arglist := make([]interface{}, 0, len(names))
for _, name := range names {
val, ok := arg[name]
if !ok {
return arglist, fmt.Errorf("could not find name %s in %#v", name, arg)
}
arglist = append(arglist, val)
}
return arglist, nil
}
// bindStruct binds a named parameter query with fields from a struct argument.
// The rules for binding field names to parameter names follow the same
// conventions as for StructScan, including obeying the `db` struct tags.
func bindStruct(bindType int, query string, arg interface{}, m *reflectx.Mapper) (string, []interface{}, error) {
bound, names, err := compileNamedQuery([]byte(query), bindType)
if err != nil {
return "", []interface{}{}, err
}
arglist, err := bindArgs(names, arg, m)
if err != nil {
return "", []interface{}{}, err
}
return bound, arglist, nil
}
var valueBracketReg = regexp.MustCompile(`\([^(]*\?+[^)]*\)`)
func fixBound(bound string, loop int) string {
loc := valueBracketReg.FindStringIndex(bound)
if len(loc) != 2 {
return bound
}
var buffer bytes.Buffer
buffer.WriteString(bound[0:loc[1]])
for i := 0; i < loop-1; i++ {
buffer.WriteString(",")
buffer.WriteString(bound[loc[0]:loc[1]])
}
buffer.WriteString(bound[loc[1]:])
return buffer.String()
}
// bindArray binds a named parameter query with fields from an array or slice of
// structs argument.
func bindArray(bindType int, query string, arg interface{}, m *reflectx.Mapper) (string, []interface{}, error) {
// do the initial binding with QUESTION; if bindType is not question,
// we can rebind it at the end.
bound, names, err := compileNamedQuery([]byte(query), QUESTION)
if err != nil {
return "", []interface{}{}, err
}
arrayValue := reflect.ValueOf(arg)
arrayLen := arrayValue.Len()
if arrayLen == 0 {
return "", []interface{}{}, fmt.Errorf("length of array is 0: %#v", arg)
}
var arglist []interface{}
for i := 0; i < arrayLen; i++ {
elemArglist, err := bindArgs(names, arrayValue.Index(i).Interface(), m)
if err != nil {
return "", []interface{}{}, err
}
arglist = append(arglist, elemArglist...)
}
if arrayLen > 1 {
bound = fixBound(bound, arrayLen)
}
// adjust binding type if we weren't on question
if bindType != QUESTION {
bound = Rebind(bindType, bound)
}
return bound, arglist, nil
}
// bindMap binds a named parameter query with a map of arguments.
func bindMap(bindType int, query string, args map[string]interface{}) (string, []interface{}, error) {
bound, names, err := compileNamedQuery([]byte(query), bindType)
if err != nil {
return "", []interface{}{}, err
}
arglist, err := bindMapArgs(names, args)
return bound, arglist, err
}
// -- Compilation of Named Queries
// Allow digits and letters in bind params; additionally runes are
// checked against underscores, meaning that bind params can have be
// alphanumeric with underscores. Mind the difference between unicode
// digits and numbers, where '5' is a digit but '五' is not.
var allowedBindRunes = []*unicode.RangeTable{unicode.Letter, unicode.Digit}
// FIXME: this function isn't safe for unicode named params, as a failing test
// can testify. This is not a regression but a failure of the original code
// as well. It should be modified to range over runes in a string rather than
// bytes, even though this is less convenient and slower. Hopefully the
// addition of the prepared NamedStmt (which will only do this once) will make
// up for the slightly slower ad-hoc NamedExec/NamedQuery.
// compile a NamedQuery into an unbound query (using the '?' bindvar) and
// a list of names.
func compileNamedQuery(qs []byte, bindType int) (query string, names []string, err error) {
names = make([]string, 0, 10)
rebound := make([]byte, 0, len(qs))
inName := false
last := len(qs) - 1
currentVar := 1
name := make([]byte, 0, 10)
for i, b := range qs {
// a ':' while we're in a name is an error
if b == ':' {
// if this is the second ':' in a '::' escape sequence, append a ':'
if inName && i > 0 && qs[i-1] == ':' {
rebound = append(rebound, ':')
inName = false
continue
} else if inName {
err = errors.New("unexpected `:` while reading named param at " + strconv.Itoa(i))
return query, names, err
}
inName = true
name = []byte{}
} else if inName && i > 0 && b == '=' && len(name) == 0 {
rebound = append(rebound, ':', '=')
inName = false
continue
// if we're in a name, and this is an allowed character, continue
} else if inName && (unicode.IsOneOf(allowedBindRunes, rune(b)) || b == '_' || b == '.') && i != last {
// append the byte to the name if we are in a name and not on the last byte
name = append(name, b)
// if we're in a name and it's not an allowed character, the name is done
} else if inName {
inName = false
// if this is the final byte of the string and it is part of the name, then
// make sure to add it to the name
if i == last && unicode.IsOneOf(allowedBindRunes, rune(b)) {
name = append(name, b)
}
// add the string representation to the names list
names = append(names, string(name))
// add a proper bindvar for the bindType
switch bindType {
// oracle only supports named type bind vars even for positional
case NAMED:
rebound = append(rebound, ':')
rebound = append(rebound, name...)
case QUESTION, UNKNOWN:
rebound = append(rebound, '?')
case DOLLAR:
rebound = append(rebound, '$')
for _, b := range strconv.Itoa(currentVar) {
rebound = append(rebound, byte(b))
}
currentVar++
case AT:
rebound = append(rebound, '@', 'p')
for _, b := range strconv.Itoa(currentVar) {
rebound = append(rebound, byte(b))
}
currentVar++
}
// add this byte to string unless it was not part of the name
if i != last {
rebound = append(rebound, b)
} else if !unicode.IsOneOf(allowedBindRunes, rune(b)) {
rebound = append(rebound, b)
}
} else {
// this is a normal byte and should just go onto the rebound query
rebound = append(rebound, b)
}
}
return string(rebound), names, err
}
// BindNamed binds a struct or a map to a query with named parameters.
// DEPRECATED: use sqlx.Named` instead of this, it may be removed in future.
func BindNamed(bindType int, query string, arg interface{}) (string, []interface{}, error) {
return bindNamedMapper(bindType, query, arg, mapper())
}
// Named takes a query using named parameters and an argument and
// returns a new query with a list of args that can be executed by
// a database. The return value uses the `?` bindvar.
func Named(query string, arg interface{}) (string, []interface{}, error) {
return bindNamedMapper(QUESTION, query, arg, mapper())
}
func bindNamedMapper(bindType int, query string, arg interface{}, m *reflectx.Mapper) (string, []interface{}, error) {
if maparg, ok := arg.(map[string]interface{}); ok {
return bindMap(bindType, query, maparg)
}
switch reflect.TypeOf(arg).Kind() {
case reflect.Array, reflect.Slice:
return bindArray(bindType, query, arg, m)
default:
return bindStruct(bindType, query, arg, m)
}
}
// NamedQuery binds a named query and then runs Query on the result using the
// provided Ext (sqlx.Tx, sqlx.Db). It works with both structs and with
// map[string]interface{} types.
func NamedQuery(e Ext, query string, arg interface{}) (*Rows, error) {
q, args, err := bindNamedMapper(BindType(e.DriverName()), query, arg, mapperFor(e))
if err != nil {
return nil, err
}
return e.Queryx(q, args...)
}
// NamedExec uses BindStruct to get a query executable by the driver and
// then runs Exec on the result. Returns an error from the binding
// or the query execution itself.
func NamedExec(e Ext, query string, arg interface{}) (sql.Result, error) {
q, args, err := bindNamedMapper(BindType(e.DriverName()), query, arg, mapperFor(e))
if err != nil {
return nil, err
}
return e.Exec(q, args...)
}
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