initial hasql support (#407)

closes #403

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
Reviewed-on: #407
Co-authored-by: Vasiliy Tolstov <v.tolstov@unistack.org>
Co-committed-by: Vasiliy Tolstov <v.tolstov@unistack.org>

cluster/hasql/db.go

@@ -0,0 +1,25 @@
+package sql
+
+import (
+	"context"
+	"database/sql"
+)
+
+type Querier interface {
+	// Basic connection methods
+	PingContext(ctx context.Context) error
+	Close() error
+
+	// Query methods with context
+	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
+	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
+	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
+
+	// Prepared statements with context
+	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
+
+	// Transaction management with context
+	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
+
+	Conn(ctx context.Context) (*sql.Conn, error)
+}