Add lesci module

1 files changed, 46 insertions, 0 deletions

diff --git a/research/lesci/append.go b/research/lesci/append.go
new file mode 100644
index 0000000..a3459ff
--- /dev/null
+++ b/research/lesci/append.go
@@ -0,0 +1,46 @@
+package lesci
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+
+	"github.com/duckdb/duckdb-go/v2"
+)
+
+type AppendFunc func([]driver.Value) error
+type AppendRowsFunc func(appendFunc AppendFunc) error
+
+func AppendRows(db *sql.DB, table string, appendRowsFunc AppendRowsFunc) error {
+	var conn *sql.Conn
+
+	if c, err := db.Conn(context.Background()); err != nil {
+		return err
+	} else {
+		conn = c
+	}
+
+	defer conn.Close()
+
+	return conn.Raw(func(driverConn any) error {
+		duckConn := driverConn.(*duckdb.Conn)
+
+		var appender *duckdb.Appender
+
+		if a, err := duckdb.NewAppenderFromConn(duckConn, "", table); err != nil {
+			return err
+		} else {
+			appender = a
+		}
+
+		defer appender.Close()
+
+		if err := appendRowsFunc(func(row []driver.Value) error {
+			return appender.AppendRow(row...)
+		}); err != nil {
+			return err
+		}
+
+		return appender.Flush()
+	})
+}