Results of 1 - 10 of about 17 for virtual (0.004 sec.)
- CREATE TABLE Statement 14190
- The CREATE TABLE statement creates a table in the catalog. Examples Create a table with two integer columns ( i and j ): CREATE TABLE t1 (i INTEGER, j INTEGER); Create a table with a primary key: CREATE TABLE t1 (id INTEGER PRIMARY KEY, j V
...raint because key "..." does not exist in the referenced table. Generated Columns The [type] [GENERATED ALWAYS] AS (expr) [VIRTUAL|STORED] syntax will create a generated column. The data in this kind of column is generated from its expression, which can...olumns might fail if the type cannot be cast to the type of the generated column. Generated columns come in two varieties: VIRTUAL and STORED . The data of virtual generated columns is not stored on disk, instead it is computed from the expression every...mputed every time the data of their dependencies change (through an INSERT / UPDATE / DROP statement). Currently, only the VIRTUAL kind is supported, and it is also the default option if the last field is left blank. The simplest syntax for a generated... - https://man.mtool.work/duckdb/2.0/sql/statements/create_table.html
- Reading and Writing Parquet Files 10328
- Examples Read a single Parquet file: SELECT * FROM 'test.parquet'; Figure out which columns/types are in a Parquet file: DESCRIBE SELECT * FROM 'test.parquet'; Create a table from a Parquet file: CREATE TABLE test AS SELECT * FROM 'test.par
...tch the glob pattern: SELECT * FROM 'test/*.parquet'; Read all files that match the glob pattern, and include the filename virtual column that specifies which file each row came from (this column is available by default without a configuration options s...xtra filename column should be included in the result. Since DuckDB 1.3.0, the filename column is added automatically as a virtual column and this option is only kept for compatibility reasons. BOOL false file_row_number Whether or not to include the fi...│ └───────────┴────────────┘ The schema parameter cannot be combined with union_by_name = true . The file_row_group_number Virtual Column New As of DuckDB 2.0, the file_row_group_number virtual column exposes the Parquet row group that each row belongs... - https://man.mtool.work/duckdb/2.0/data/parquet/overview.html
- Run Queries 10104
- Overview DuckDB-Wasm provides functions for querying data. Queries are run sequentially: First, create a connection by calling connect . Then, run queries by calling query to materialize the whole result, or send to fetch result chunks lazi
...onnection to release memory await conn.close(); Export Parquet To export a query result, write it to a Parquet file in the virtual file system with COPY , then copy that file's bytes into a buffer you can download or process: // Create a new connection...const conn = await db.connect(); // Export the query result to a Parquet file in the virtual file system await conn.query(`COPY (SELECT * FROM tbl) TO 'result-snappy.parquet' (FORMAT parquet);`); // Copy the file co... - https://man.mtool.work/duckdb/2.0/clients/wasm/query.html
- Importing Data 10104
- The first step to using a database system is to insert data into that system. DuckDB can directly connect to many popular data sources and offers several data ingestion methods that allow you to easily and efficiently fill up the database.
...e page on JSON loading . Returning the Filename Since DuckDB 1.3.0, the CSV, JSON and Parquet readers support the filename virtual column: COPY (FROM (VALUES (42), (43)) t(x)) TO 'test.parquet'; SELECT *, filename FROM 'test.parquet'; Returning the File...Index The CSV, JSON and Parquet readers also support the file_index virtual column, which returns the zero-based index of the file that each row came from, in the order the files were read: COPY (FR... - https://man.mtool.work/duckdb/2.0/data/overview.html
- Tigris Import 8966
- Prerequisites For Tigris , the S3-compatible API allows you to use DuckDB's S3 support to read and write from Tigris buckets. This requires the httpfs extension , which can be installed using the INSTALL SQL command. This only needs to be r
...required for request signing but is not used for routing — set it to auto . URL_STYLE does not need to be set. Tigris uses virtual-hosted-style URLs, which is DuckDB's default for TYPE s3 . Tip When DuckDB runs on a Fly.io Machine, requests to fly.stora... - https://man.mtool.work/duckdb/2.0/guides/network_cloud_storage/tigris_import.htm...
- JSON Processing Functions 8742
- JSON Extraction Functions There are two extraction functions, which have their respective operators. The operators can only be used if the string is stored as the JSON logical type. These functions support the same two location notations as
...rent UBIGINT id of parent element fullkey VARCHAR JSON path to element path VARCHAR JSON path to parent element json JSON (Virtual) The json parameter root TEXT (Virtual) The path parameter rowid BIGINT (Virtual) The row identifier These functions are a... - https://man.mtool.work/duckdb/2.0/data/json/json_functions.html
- Relational API 8293
- The Relational API builds a query one step at a time from Python. A relation, a DuckDBPyRelation , is a piece of SQL text: the methods of the Transformation and Functions sections return a new relation whose text extends the one they were c
...as a table, with the footer __repr__ prints for the relation. query Run the given SQL query in sql_query on the view named virtual_table_name that refers to the relation object. set_alias Rename the relation object to new alias. shape Tuple of # of rows...ng │ 8 │ false │ │ 3 │ jacket │ clothing │ 65 │ true │ └───────┴─────────┴──────────┴───────┴──────────┘ query query(self, virtual_table_name: str, sql_query: str) -> DuckDBPyRelation | None Run the given SQL query in sql_query on the view named virtual...cludes a SELECT whose common table expression writes, runs at the call and the relation holds what it returned. Parameters virtual_table_name : str The name under which sql_query reads the relation. * sql_query : str The SQL query, a single statement, t... - https://man.mtool.work/duckdb/2.0/clients/python/relational_api.html
- JSON Overview 8293
- DuckDB supports SQL functions that are useful for reading values from existing JSON and creating new JSON data. JSON is supported with the json extension which is shipped with most DuckDB distributions and is auto-loaded on first use. If yo
...SELECT clause : CREATE TABLE todos AS SELECT * FROM 'todos.json'; Since DuckDB 1.3.0, the JSON reader returns the filename virtual column: SELECT filename, * FROM 'todos-*.json'; Writing JSON Write the result of a query to a JSON file: COPY (SELECT * FR... - https://man.mtool.work/duckdb/2.0/data/json/overview.html
- DuckDB Wasm Client 7845
- Installation To use the DuckDB Wasm client, visit the duckdb-wasm GitHub repository . The latest stable version of the DuckDB WebAssembly client is 2.0.0. DuckDB-Wasm is a version of DuckDB that has been compiled to WebAssembly , the portab
...teroperate with other JavaScript data tools without reimplementing SQL type logic in JavaScript. DuckDB-Wasm is built on a virtual filesystem that treats local files, remote HTTP(S) servers and in-memory buffers uniformly. Because DuckDB understands fil... - https://man.mtool.work/duckdb/2.0/clients/wasm/overview.html
- Python Client API 7621
- Connection class duckdb. Appender Bases: object append_row ( self , * args ) → None Buffer one row, one value per column, each converted as an executemany parameter would be append_rows ( self , rows : object ) → None Buffer each row of an
...Computes the exact quantile value for a given expression. Detailed examples can be found at Relational API page . query ( virtual_table_name : str , sql_query : str ) → DuckDBPyRelation | None Run the given SQL query in sql_query on the view named virt...pender that buffers rows of the declared columns and runs the DML over them at each flush duckdb. query_df ( df : object , virtual_table_name : str , sql_query : str , * , connection : DuckDBPyConnection | None = None ) → DuckDBPyRelation | None Run the...given SQL query in sql_query on the view named virtual_table_name that refers to the relation object. duckdb. query_progress ( * , connection : _duckdb.DuckDBPyConnection | None... - https://man.mtool.work/duckdb/2.0/clients/python/reference/
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