Use db.GetDialect to read zero or one row using driver-specific SQL selected from db.DialectSQL.

GetDialect

Use db.GetDialect when you want to read zero or one row from a db.DialectSQL query.

GetDialect selects the correct SQL or CQL text for the active driver and scans the returned row into a typed Go value.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

if !found {
	return User{}, false, nil
}

Function

func GetDialect[T any](ctx context.Context, c db.DialectQuerier, q db.DialectSQL, args ...any) (T, bool, error)

GetDialect accepts:

a context.Context
a dialect-capable connection
a db.DialectSQL value
optional query arguments

It returns:

T, found, error

found is false when the query returns no rows.

When to Use GetDialect

Use db.GetDialect when:

the query should return one row or no rows
the application may run with different database drivers
SQL syntax differs between drivers
placeholder styles differ between drivers
queries are loaded from SQL model files
a missing row is a normal application case

For direct query strings, use db.Get.

For query objects, use db.GetQuery.

Define a Model

type User struct {
	ID        int64     `db:"id"`
	Name      string    `db:"name"`
	Email     string    `db:"email"`
	Active    bool      `db:"active"`
	CreatedAt time.Time `db:"created_at"`
}

Define Query Model

A query model stores one logical query with driver-specific SQL.

type Queries struct {
	GetUser db.DialectSQL `json:"GetUser"`
}

Application code should usually pass the whole db.DialectSQL value to db.GetDialect.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

SQL File Example

For MySQL, model.sql may contain:

--GetUser
SELECT *
FROM users
WHERE id = ?
LIMIT 1

For PostgreSQL, model.psql may contain:

--GetUser
SELECT *
FROM users
WHERE id = $1
LIMIT 1

For Scylla, model.cql may contain:

--GetUser
SELECT *
FROM users_by_id
WHERE id = ?
LIMIT 1

Load Queries

Load the query model with db.LoadModel.

func LoadQueries(conn db.Conn) (Queries, error) {
	var queries Queries

	if err := db.LoadModel(conn, ".", &queries); err != nil {
		return Queries{}, err
	}

	return queries, nil
}

The active driver decides which model file is loaded:

model.sql  -> MySQL
model.psql -> PostgreSQL
model.cql  -> Scylla

Complete Query Example

This example loads the query model and uses db.GetDialect.

package main

import (
	"context"
	"time"

	"github.com/netlifeguru/db"
)

type User struct {
	ID        int64     `db:"id"`
	Name      string    `db:"name"`
	Email     string    `db:"email"`
	Active    bool      `db:"active"`
	CreatedAt time.Time `db:"created_at"`
}

type Queries struct {
	GetUser db.DialectSQL `json:"GetUser"`
}

func LoadQueries(conn db.Conn) (Queries, error) {
	var queries Queries

	if err := db.LoadModel(conn, ".", &queries); err != nil {
		return Queries{}, err
	}

	return queries, nil
}

func GetUserDialect(ctx context.Context, conn db.Conn, queries Queries, id int64) (User, bool, error) {
	return db.GetDialect[User](ctx, conn, queries.GetUser, id)
}

Complete Usage Example

This example connects to the database, loads SQL from the active driver model, and reads one user.

package main

import (
	"context"
	"fmt"
	"log"

	_ "github.com/go-sql-driver/mysql"
	"github.com/joho/godotenv"
)

func main() {
	err := godotenv.Load()
	if err != nil {
		log.Println(".env file not found, I'm using system env variables")
	}

	conn, err := connectDB()
	if err != nil {
		log.Fatal(err)
	}

	ctx := context.Background()

	queries, err := LoadQueries(conn)
	if err != nil {
		log.Fatal(err)
	}

	user, found, err := GetUserDialect(ctx, conn, queries, 1)
	if err != nil {
		log.Fatal(err)
	}

	if !found {
		log.Println("user not found")
		return
	}

	fmt.Printf(
		"ID: %d | Name: %s | Email: %s | Active: %t | Created: %s\n",
		user.ID,
		user.Name,
		user.Email,
		user.Active,
		user.CreatedAt.Format("2006-01-02 15:04:05"),
	)
}

Not Found

db.GetDialect does not return an error when no row is found.

Instead, it returns found = false.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

if !found {
	return User{}, false, nil
}

This is useful for optional lookups.

Too Many Rows

db.GetDialect expects zero or one row.

If the selected query returns more than one row, it returns an error.

Use a unique condition or LIMIT 1 when only one row should be returned.

SELECT *
FROM users
WHERE id = ?
LIMIT 1

Avoid LIMIT 1 when duplicate rows should be detected by the application.

Driver Selection

GetDialect selects the query field based on the active driver.

Active driver	Selected query
MySQL	`queries.GetUser.Mysql`
Postgres	`queries.GetUser.Postgres`
Scylla	`queries.GetUser.Scylla`

If the selected query is empty, GetDialect returns an error.

Arguments

Arguments are passed to the selected query.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

For MySQL, the selected query may use:

WHERE id = ?

For PostgreSQL:

WHERE id = $1

For Scylla:

WHERE id = ?

The Go call stays the same, but the SQL or CQL text must match the active driver.

Low-Level Equivalent

GetDialect is a convenience helper.

This:

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

is equivalent to:

q, err := db.Dialect(conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

user, found, err := db.GetQuery[User](ctx, conn, q)
if err != nil {
	return User{}, false, err
}

Use the low-level form when you need access to the selected db.Query.

Use db.ListDialect when the dialect query can return multiple rows.

users, err := db.ListDialect[User](ctx, conn, queries.ListUsers, 10)

Use db.ValueDialect when the dialect query returns one scalar value.

total, found, err := db.ValueDialect[int64](ctx, conn, queries.CountUsers)

Use db.MapsDialect when the dialect query returns dynamic map rows.

rows, err := db.MapsDialect(ctx, conn, queries.EventsReport, 10)

Standalone examples are available in the examples repository:

Dialect Get

GetDialect

Use db.GetDialect when you want to read zero or one row from a db.DialectSQL query.

GetDialect selects the correct SQL or CQL text for the active driver and scans the returned row into a typed Go value.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

if !found {
	return User{}, false, nil
}

Function

func GetDialect[T any](ctx context.Context, c db.DialectQuerier, q db.DialectSQL, args ...any) (T, bool, error)

GetDialect accepts:

a context.Context
a dialect-capable connection
a db.DialectSQL value
optional query arguments

It returns:

T, found, error

found is false when the query returns no rows.

When to Use GetDialect

Use db.GetDialect when:

the query should return one row or no rows
the application may run with different database drivers
SQL syntax differs between drivers
placeholder styles differ between drivers
queries are loaded from SQL model files
a missing row is a normal application case

For direct query strings, use db.Get.

For query objects, use db.GetQuery.

Define a Model

type User struct {
	ID        int64     `db:"id"`
	Name      string    `db:"name"`
	Email     string    `db:"email"`
	Active    bool      `db:"active"`
	CreatedAt time.Time `db:"created_at"`
}

Define Query Model

A query model stores one logical query with driver-specific SQL.

type Queries struct {
	GetUser db.DialectSQL `json:"GetUser"`
}

Application code should usually pass the whole db.DialectSQL value to db.GetDialect.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

SQL File Example

For MySQL, model.sql may contain:

--GetUser
SELECT *
FROM users
WHERE id = ?
LIMIT 1

For PostgreSQL, model.psql may contain:

--GetUser
SELECT *
FROM users
WHERE id = $1
LIMIT 1

For Scylla, model.cql may contain:

--GetUser
SELECT *
FROM users_by_id
WHERE id = ?
LIMIT 1

Load Queries

Load the query model with db.LoadModel.

func LoadQueries(conn db.Conn) (Queries, error) {
	var queries Queries

	if err := db.LoadModel(conn, ".", &queries); err != nil {
		return Queries{}, err
	}

	return queries, nil
}

The active driver decides which model file is loaded:

model.sql  -> MySQL
model.psql -> PostgreSQL
model.cql  -> Scylla

Complete Query Example

This example loads the query model and uses db.GetDialect.

package main

import (
	"context"
	"time"

	"github.com/netlifeguru/db"
)

type User struct {
	ID        int64     `db:"id"`
	Name      string    `db:"name"`
	Email     string    `db:"email"`
	Active    bool      `db:"active"`
	CreatedAt time.Time `db:"created_at"`
}

type Queries struct {
	GetUser db.DialectSQL `json:"GetUser"`
}

func LoadQueries(conn db.Conn) (Queries, error) {
	var queries Queries

	if err := db.LoadModel(conn, ".", &queries); err != nil {
		return Queries{}, err
	}

	return queries, nil
}

func GetUserDialect(ctx context.Context, conn db.Conn, queries Queries, id int64) (User, bool, error) {
	return db.GetDialect[User](ctx, conn, queries.GetUser, id)
}

Complete Usage Example

This example connects to the database, loads SQL from the active driver model, and reads one user.

package main

import (
	"context"
	"fmt"
	"log"

	_ "github.com/go-sql-driver/mysql"
	"github.com/joho/godotenv"
)

func main() {
	err := godotenv.Load()
	if err != nil {
		log.Println(".env file not found, I'm using system env variables")
	}

	conn, err := connectDB()
	if err != nil {
		log.Fatal(err)
	}

	ctx := context.Background()

	queries, err := LoadQueries(conn)
	if err != nil {
		log.Fatal(err)
	}

	user, found, err := GetUserDialect(ctx, conn, queries, 1)
	if err != nil {
		log.Fatal(err)
	}

	if !found {
		log.Println("user not found")
		return
	}

	fmt.Printf(
		"ID: %d | Name: %s | Email: %s | Active: %t | Created: %s\n",
		user.ID,
		user.Name,
		user.Email,
		user.Active,
		user.CreatedAt.Format("2006-01-02 15:04:05"),
	)
}

Not Found

db.GetDialect does not return an error when no row is found.

Instead, it returns found = false.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

if !found {
	return User{}, false, nil
}

This is useful for optional lookups.

Too Many Rows

db.GetDialect expects zero or one row.

If the selected query returns more than one row, it returns an error.

Use a unique condition or LIMIT 1 when only one row should be returned.

SELECT *
FROM users
WHERE id = ?
LIMIT 1

Avoid LIMIT 1 when duplicate rows should be detected by the application.

Driver Selection

GetDialect selects the query field based on the active driver.

Active driver	Selected query
MySQL	`queries.GetUser.Mysql`
Postgres	`queries.GetUser.Postgres`
Scylla	`queries.GetUser.Scylla`

If the selected query is empty, GetDialect returns an error.

Arguments

Arguments are passed to the selected query.

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

For MySQL, the selected query may use:

WHERE id = ?

For PostgreSQL:

WHERE id = $1

For Scylla:

WHERE id = ?

The Go call stays the same, but the SQL or CQL text must match the active driver.

Low-Level Equivalent

GetDialect is a convenience helper.

This:

user, found, err := db.GetDialect[User](ctx, conn, queries.GetUser, id)

is equivalent to:

q, err := db.Dialect(conn, queries.GetUser, id)
if err != nil {
	return User{}, false, err
}

user, found, err := db.GetQuery[User](ctx, conn, q)
if err != nil {
	return User{}, false, err
}

Use the low-level form when you need access to the selected db.Query.

Use db.ListDialect when the dialect query can return multiple rows.

users, err := db.ListDialect[User](ctx, conn, queries.ListUsers, 10)

Use db.ValueDialect when the dialect query returns one scalar value.

total, found, err := db.ValueDialect[int64](ctx, conn, queries.CountUsers)

Use db.MapsDialect when the dialect query returns dynamic map rows.

rows, err := db.MapsDialect(ctx, conn, queries.EventsReport, 10)

Standalone examples are available in the examples repository:

Dialect Get

GetDialect

GetDialect

Function

When to Use GetDialect

Define a Model

Define Query Model

SQL File Example

Load Queries

Complete Query Example

Complete Usage Example

Not Found

Too Many Rows

Driver Selection

Arguments

Low-Level Equivalent

On this page

GetDialect

GetDialect

Function

When to Use GetDialect

Define a Model

Define Query Model

SQL File Example

Load Queries

Complete Query Example

Complete Usage Example

Not Found

Too Many Rows

Driver Selection

Arguments

Low-Level Equivalent

On this page