Results of 1 - 9 of about 9 for Of course (0.002 sec.)
of (404), course (9)
- Subqueries 17752
- Subqueries are parenthesized query expressions that appear as part of a larger, outer query. Subqueries are usually based on SELECT ... FROM , but in DuckDB other query constructs such as PIVOT can also appear as a subquery. Scalar Subquery
...calar subquery returns more than a single value, an error is raised (unless scalar_subquery_error_on_multiple_rows is set to false , in which case a row is selected randomly). Consider the following table: Grades grade course 7 Math 9 Math 8 CS CRE...ATE TABLE grades (grade INTEGER, course VARCHAR); INSERT INTO grades VALUES (7, 'Math'), (9, 'Math'), (8, 'CS'); We can run the following query to obtain the mini...e: SELECT min(grade) FROM grades; min(grade) 7 By using a scalar subquery in the WHERE clause, we can figure out for which course this grade was obtained: SELECT course FROM grades WHERE grade = (SELECT min(grade) FROM grades); course Math ARRAY Subque... - https://man.mtool.work/duckdb/2.0/sql/expressions/subqueries.html
- GROUPING SETS 16643
- GROUPING SETS , ROLLUP and CUBE can be used in the GROUP BY clause to perform a grouping over multiple dimensions within the same query. Note that this syntax is not compatible with GROUP BY ALL . Examples Compute the average income along t
...tion GROUPING SETS performs the same aggregate across different GROUP BY clauses in a single query. CREATE TABLE students (course VARCHAR, type VARCHAR); INSERT INTO students (course, type) VALUES ('CS', 'Bachelor'), ('CS', 'Bachelor'), ('CS', 'PhD'),...('Math', 'Masters'), ('CS', NULL), ('CS', NULL), ('Math', NULL); SELECT course, type, count(*) FROM students GROUP BY GROUPING SETS ((course, type), course, type, ()); course type count_star() Math NUL...or a group which is not in the grouping set for the result, i.e., the above query is equivalent to the following statement of UNION ALL clauses: -- Group by course, type: SELECT course, type, count(*) FROM students GROUP BY course, type UNION ALL -... - https://man.mtool.work/duckdb/2.0/sql/query_syntax/grouping_sets.html
- Geometry Data Type 13571
- Name Description GEOMETRY Geospatial entity The GEOMETRY data type is used to store and manipulate geometric objects, such as points, lines, and polygons. The GEOMETRY type was part of the spatial extension but became a built-in data type i
...n DuckDB 1.5. Most of the benefits of having GEOMETRY as a built-in type (e.g., storage optimizations, statistics, etc.) are therefore only avai...lable in databases using storage version v1.5 and above. However, almost all of the associated functions for working with geometries (e.g., calculating distances, areas, intersections) are still part of...no_crs │ │ geometry │ ├───────────────────────────┤ │ POINT (4.89707 52.377956) │ └───────────────────────────┘ You can of course also use ST_CRS(geom) to retrieve the CRS of a geometry: SELECT ST_CRS('POINT(4.897070 52.377956)'::GEOMETRY('OGC:CRS84'))... - https://man.mtool.work/duckdb/2.0/sql/data_types/geometry.html
- Avro Extension 13351
- The avro extension enables DuckDB to read Apache Avro files. The avro extension was released as a community extension in late 2024 and became a core extension in early 2025. The read_avro Function The extension adds a single DuckDB function
...read_avro . This function can be used like so: FROM read_avro('⟨some_file⟩.avro'); This function will expose the contents of the Avro file as a DuckDB table. You can then use any arbitrary SQL constructs to further transform this table. File IO Th...e read_avro function is integrated into DuckDB's file system abstraction, meaning you can read Avro files directly from, e.g., HTTP or...NULL as a union of the actual type with a special NULL type. This is different to DuckDB, where any value can be NULL . Of course DuckDB also supports UNION types, but this would be quite cumbersome to work with. This extension simplifies the Avro sche... - https://man.mtool.work/duckdb/2.0/core_extensions/avro.html
- SQL Introduction 13333
- This page provides an overview of how to perform simple operations in SQL. This tutorial is only intended to give you an introduction and is in no way a complete tutorial on SQL. This tutorial is adapted from the PostgreSQL tutorial . DuckD
...B's SQL dialect closely follows the conventions of the PostgreSQL dialect. The few exceptions to this are listed on the PostgreSQL compatibility page . In the examples that...formation on how to install the CLI. Tip If you are looking for a comprehensive to SQL introduction, check the slide decks of the “Tabular Database Systems” course : The Structured Query Language (SQL) More SQL (Subqueries + Embedded SQL) SQL: Grou... - https://man.mtool.work/duckdb/2.0/sql/introduction.html
- ODBC 101: A Duck Themed Guide to ODBC 12444
- What is ODBC? ODBC which stands for Open Database Connectivity, is a standard that allows different programs to talk to different databases including, of course, DuckDB. This makes it easier to build programs that work with many different d
...ch reduces development time and costs, and programs are easier to maintain. However, ODBC can be slower than other methods of connecting to a database, such as using a native driver, as it adds an extra layer of abstraction between the application...BC is row-based, there can be some inefficiencies when using ODBC with DuckDB. There are links throughout this page to the official Microsoft ODBC documentation , which is a great resource for learning more about ODBC. General Concepts Handles Conn... - https://man.mtool.work/duckdb/2.0/guides/odbc/general.html
- Excel Export 12125
- DuckDB supports exporting data to Excel .xlsx files via the excel extension. Please note that .xls files are not supported. To install and load the extension, run: INSTALL excel; LOAD excel; Exporting Excel Sheets To export a table to an Ex
...cel file, use the COPY statement with the FORMAT xlsx option: COPY tbl TO 'output.xlsx' WITH (FORMAT xlsx); The result of a query can also be directly exported to an Excel file: COPY (SELECT * FROM tbl) TO 'output.xlsx' WITH (FORMAT xlsx); Or:...MAT xlsx, SHEET 'Sheet1'); Type Conversions Because Excel only really supports storing numbers or strings – the equivalent of VARCHAR and DOUBLE , the following type conversions are automatically applied when writing XLSX files: Numeric types are c...them appear as TRUE and FALSE in Excel. All other types are cast to VARCHAR and then written as text cells. But you can of course also explicitly cast columns to a different type before exporting them to Excel: COPY (SELECT CAST(a AS VARCHAR), b FROM t... - https://man.mtool.work/duckdb/2.0/guides/file_formats/excel_export.html
- Performance Guide 11845
- DuckDB aims to automatically achieve high performance by using well-chosen default configurations and having a forgiving architecture. Of course, there are still opportunities for tuning the system for specific workloads. The Performance Gu
... - https://man.mtool.work/duckdb/2.0/guides/performance/overview.html
- Handle Results 11510
- 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
...sultSet; // Arrow binding try (var allocator = new RootAllocator(); ArrowStreamReader reader = null; // should not be null of course var arrow_array_stream = ArrowArrayStream.allocateNew(allocator)) { Data.exportArrayStream(allocator, reader, arrow...he Properties object. Properties props = new Properties(); props.setProperty(DuckDBDriver.JDBC_STREAM_RESULTS, String.valueOf(true)); Connection conn = DriverManager.getConnection("jdbc:duckdb:", props); Chunked Results The JDBC driver can return a... - https://man.mtool.work/duckdb/2.0/clients/java/result_handling.html
PREV
1
NEXT
DuckDB 2.0 Documentation / man.mtool.work