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Improve formatting

Olivier Mengué 2020-02-28 11:35:44 +01:00
parent df33a22130
commit e572ac21bd
1 changed files with 13 additions and 10 deletions
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23
SQLInterface.md

@ -36,11 +36,12 @@ if err := db.PingContext(ctx); err != nil {
} }
``` ```
After use, the database is closed using `Close`. After use, the database is closed using [`Close`](https://golang.org/pkg/database/sql/#DB.Close).
# Executing queries # Executing queries
ExecContext is used for queries where no rows are returned: [`ExecContext`](https://golang.org/pkg/database/sql/#DB.ExecContext)
is used for queries where no rows are returned:
```go ```go
result, err := db.ExecContext(ctx, result, err := db.ExecContext(ctx,
@ -54,7 +55,8 @@ Where result contains the last insert ID and number of
rows affected. The availability of these values is dependent on rows affected. The availability of these values is dependent on
the database driver. the database driver.
QueryContext is used for retrieval: [`QueryContext`](https://golang.org/pkg/database/sql/#DB.QueryContext)
is used for retrieval:
```go ```go
rows, err := db.QueryContext(ctx, "SELECT name FROM users WHERE age = $1", age) rows, err := db.QueryContext(ctx, "SELECT name FROM users WHERE age = $1", age)
@ -74,14 +76,15 @@ if err := rows.Err(); err != nil {
} }
``` ```
QueryRowContext is used where only a single row is expected: [`QueryRowContext`](https://golang.org/pkg/database/sql/#DB.QueryRowContext)
is used where only a single row is expected:
```go ```go
var age int64 var age int64
err := db.QueryRowContext(ctx, "SELECT age FROM users WHERE name = $1", name).Scan(&age) err := db.QueryRowContext(ctx, "SELECT age FROM users WHERE name = $1", name).Scan(&age)
``` ```
Prepared statements can be created with Prepare: Prepared statements can be created with [`PrepareContext`](https://golang.org/pkg/database/sql/#DB.PrepareContext):
```go ```go
age := 27 age := 27
@ -93,12 +96,12 @@ rows, err := stmt.Query(age)
// process rows // process rows
``` ```
ExecContext, QueryContext and QueryRowContext can be called on statements. After use, a [`ExecContext`](https://golang.org/pkg/database/sql/#Stmt.ExecContext), [`QueryContext`](https://golang.org/pkg/database/sql/#Stmt.QueryContext) and [`QueryRowContext`](https://golang.org/pkg/database/sql/#Stmt.QueryContext) can be called on statements. After use, a
statement should be closed with Close. statement should be closed with [`Close`](https://golang.org/pkg/database/sql/#Stmt.Close).
# Transactions # Transactions
Transactions are started with Begin: Transactions are started with [`BeginTx`](https://golang.org/pkg/database/sql/#DB.BeginTx):
```go ```go
tx, err := db.BeginTx(ctx, nil) tx, err := db.BeginTx(ctx, nil)
@ -107,10 +110,10 @@ if err != nil {
} }
``` ```
The ExecContext, QueryContext, QueryRowContext and PrepareContext functions already covered can be The [`ExecContext`](https://golang.org/pkg/database/sql/#Tx.ExecContext), [`QueryContext`](https://golang.org/pkg/database/sql/#Tx.QueryContext), [`QueryRowContext`](https://golang.org/pkg/database/sql/#Tx.QueryRowContext) and [`PrepareContext`](https://golang.org/pkg/database/sql/#Tx.PrepareContext) methods already covered can be
used in a transaction. used in a transaction.
A transaction must end with a call to Commit or Rollback. A transaction must end with a call to [`Commit`](https://golang.org/pkg/database/sql/#Tx.Commit) or [`Rollback`](https://golang.org/pkg/database/sql/#Tx.Rollback).
# Dealing with NULL # Dealing with NULL