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- C++ API 12408
- Installation To use the DuckDB C++ API, download the libduckdb archive for your platform. The latest stable version of the DuckDB C++ API is 2.0.0. Warning DuckDB's C++ API is internal. It is not guaranteed to be stable and can change witho
...ined using the next field. Because Query() retains the full result, the result set can be traversed directly by index. Use ColumnCount() and RowCount() for the dimensions, and Collection().GetValue(column, row) to retrieve an individual value as a duckdb::V...< result->GetError() << endl; } else { // Print the column names as a header row for (idx_t col_idx = 0; col_idx < result->ColumnCount(); col_idx++) { cout << result->GetNames()[col_idx]; cout << (col_idx + 1 < result->ColumnCount() ? "\t" : "\n"); } // Ite...alized result for (idx_t row_idx = 0; row_idx < result->RowCount(); row_idx++) { for (idx_t col_idx = 0; col_idx < result->ColumnCount(); col_idx++) { // GetValue returns a duckdb::Value; ToString renders it (NULL values become "NULL") cout << result->Colle... - https://man.mtool.work/duckdb/2.0/clients/cpp.html
- Node.js Client (Neo) 8525
- Installation To use the DuckDB Node.js client, visit the Node.js installation page . The latest stable version of the DuckDB Node.js (Neo) client is 2.0.0. An API for using DuckDB in Node.js . The primary package, @duckdb/node-api , is a hi
...= chunk.getColumnsObject(result.deduplicatedColumnNames()); Get chunk data (one value at a time) const columns = []; const columnCount = chunk.columnCount; for (let columnIndex = 0; columnIndex < columnCount; columnIndex++) { const columnValues = []; const... - https://man.mtool.work/duckdb/2.0/clients/node_neo/overview.html
- Handle Results 8229
- Overview Beyond the standard JDBC ResultSet , the DuckDB driver can hand results to Apache Arrow , stream large results instead of materializing them, and expose raw columnar data chunks. This page covers each of these result-handling optio
...ChunkReader chunk = res.chunk(); // iterate over the chunk columns, all indices are 0-based for (long col = 0; col < chunk.columnCount(); col++) { // get a vector for the specified column DuckDBReadableVector vector = chunk.vector(col); // iterate over the... - https://man.mtool.work/duckdb/2.0/clients/java/result_handling.html
- Write User Defined Functions 7785
- Overview The JDBC driver can register user-defined functions (UDFs) written in Java, including scalar functions and table functions. This page covers building and registering both, from the simple functional-interface overloads to the vecto
...rest. for (; row < output.capacity() && cursor.next < cursor.end; row++, cursor.next++) { for (long col = 0; col < output.columnCount(); col++) { DuckDBWritableVector vector = output.vector(col); switch (vector.getType()) { case BIGINT: vector.setLong(row,...e rest. When pushdown is enabled, the init callback learns the projected columns from its DuckDBTableFunctionInitInfo : getColumnCount() returns the number of columns the query requires, and getColumnIndex(position) maps each projected position back to the...o) throws Exception { // Record which declared columns the query actually needs. long[] projected = new long[(int) info.getColumnCount()]; for (int i = 0; i < projected.length; i++) { projected[i] = info.getColumnIndex(i); } return projected; } // ... apply... - https://man.mtool.work/duckdb/2.0/clients/java/functions.html
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