README
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sqldb
sqldb is a helper to connect to SQL database server.
It follows the design pattern where write operation will be directed to master DB while the read one to follower DB. This pattern will improve the read scalability because follower DB can be scaled horizontally in easy way while still maintaining data consistency which written to the master.
Write to Master, Read from Follower
In sqldb, all select, get and query will come to follower database. All exec is coming to master. Or equivalent to DDL and DML is going to master and data retrieval is going to follower.
If follower DSN is not specified, then follower will be the same as master.
Single Master - Follower model
sqldb only recognize one master database. This means sqldb is not suitable for multi-master database model.
Usage example
For initializing
dbclient, err := sqldb.Connect(context.Background(), sqldb.DBConfig{
Driver: "mysql", // depends on the engine, currently support postgresql and
MasterDSN: "username:password@tcp(host:port)/database_name",
SlaveDSN: "username:password@tcp(host:port)/database_name",
MaxOpenConnections: 100, // if 0, it will use default config
MaxIdleConnections: 10, // if 0, it will use default config
ConnectionMaxLifetime: 10 * time.Second,
Retry: 3,
})
if err != nil {
log.Println("error initialize db client, err : ", err)
return
}
log.Println("database connected !!")
for any other example, you can check on example/sqlexample folder
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type DBConfig ¶
type DBConfig struct {
Driver DBEngine `json:"driver" yaml:"driver"`
MasterDSN string `json:"master" yaml:"master"`
SlaveDSN string `json:"slave" yaml:"slave"`
MaxOpenConnections int `json:"max_open_conns" yaml:"max_open_conns"`
MaxIdleConnections int `json:"max_idle_conns" yaml:"max_idle_conns"`
ConnectionMaxLifetime time.Duration `json:"conn_max_lifetime" yaml:"conn_max_lifetime"`
Retry int `json:"retry" yaml:"retry"`
}
type Master ¶
type Master interface {
Exec(query string, args ...interface{}) (sql.Result, error)
// ExecContext use master database to exec query
ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
// Begin transaction on master DB
Begin() (*sql.Tx, error)
// BeginTx begins transaction on master DB
BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
// Rebind a query from the default bindtype (QUESTION) to the target bindtype.
Rebind(sql string) string
// NamedExec do named exec on master DB
NamedExec(query string, arg interface{}) (sql.Result, error)
// NamedExecContext do named exec on master DB
NamedExecContext(ctx context.Context, query string, arg interface{}) (sql.Result, error)
// BindNamed do BindNamed on master DB
BindNamed(query string, arg interface{}) (string, []interface{}, error)
}
Master defines operation that will be executed to master DB
type Slave ¶
type Slave interface {
// Get from slave database
Get(dest interface{}, query string, args ...interface{}) error
// Select from slave database
Select(dest interface{}, query string, args ...interface{}) error
// Query from slave database
Query(query string, args ...interface{}) (*sql.Rows, error)
// QueryRow executes QueryRow against slave DB
QueryRow(query string, args ...interface{}) *sql.Row
// NamedQuery do named query on slave DB
NamedQuery(query string, arg interface{}) (*sqlx.Rows, error)
// GetContext from sql database
GetContext(ctx context.Context, dest interface{}, query string, args ...interface{}) error
// SelectContext from sql database
SelectContext(ctx context.Context, dest interface{}, query string, args ...interface{}) error
// QueryContext from sql database
QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
// QueryRowContext from sql database
QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
// QueryxContext queries the database and returns an *sqlx.Rows. Any placeholder parameters are replaced with supplied args.
QueryxContext(ctx context.Context, query string, args ...interface{}) (*sqlx.Rows, error)
// QueryRowxContext queries the database and returns an *sqlx.Row. Any placeholder parameters are replaced with supplied args.
QueryRowxContext(ctx context.Context, query string, args ...interface{}) *sqlx.Row
// NamedQueryContext do named query on slave DB
NamedQueryContext(ctx context.Context, query string, arg interface{}) (*sqlx.Rows, error)
}
Slave defines operation that will be executed to slave DB
Source Files