Results of 1 - 10 of about 169 for Types (0.002 sec.)
- CSV Auto Detection 10915
- When using read_csv , the system tries to automatically infer how to read the CSV file using the CSV sniffer . This step is necessary because CSV files are not self-describing and come in many different dialects. The auto-detection works ro
...ughly as follows: Detect the dialect of the CSV file (delimiter, quoting rule, escape). Detect the types of each of the columns. Detect whether or not the file has a header row. By default the system will try to auto-detect all...aracter comment # SkipRows Number of rows skipped skip 1 HasHeader Whether the CSV has a header header true Columns Column types encoded as a LIST of STRUCT s columns ({'name': 'VARCHAR', 'age': 'BIGINT'}) DateFormat Date format dateformat %d/%m/%Y Ti...was actually found in the CSV file. Type Detection After detecting the dialect, the system will attempt to figure out the types of each of the columns. Note that this step is only performed if we are calling read_csv . In case of the COPY statement t... - https://man.mtool.work/duckdb/2.0/data/csv/auto_detection.html
- Union Type 10824
- A UNION type (not to be confused with the SQL UNION operator ) is a nested type capable of holding one of multiple “alternative” values, much like the union in C. The main difference is that these UNION types are tagged unions and thus alwa
...discriminator “tag” which signals which alternative it is currently holding, even if the inner value itself is null. UNION types are thus more similar to C++17's std::variant , Rust's Enum or the “sum type” present in most functional languages. UNION...ave at least one member, and while they can contain multiple members of the same type, the tag names must be unique. UNION types can have at most 255 members. Under the hood, UNION types are implemented on top of STRUCT types, and simply keep the “tag...another UNION if the source UNION members are a subset of the target's (if the cast is unambiguous). UNION uses the member types' VARCHAR cast functions when casting to VARCHAR : SELECT u FROM tbl1; u 1 two three Select all the str members: SELECT uni... - https://man.mtool.work/duckdb/2.0/sql/data_types/union.html
- Data Types 9751
- General-Purpose Data Types The table below shows all the built-in general-purpose data types. The alternatives listed in the aliases column can be used to refer to these types as well, however, note that the aliases are not part of the SQL
...R , BPCHAR , TEXT , STRING Variable-length character string Implicit and explicit typecasting is possible between numerous types, see the Typecasting page for details. Nested / Composite Types DuckDB supports the following nested data types: ARRAY , L...s, each key having the same type and each value having the same type. Keys and values can be any type and can be different types from one another. Rows may have different keys. map([1, 2], ['a', 'b']) MAP(INTEGER, VARCHAR) STRUCT A dictionary of multi...on, where the value can be a different type for each position. Each row must have the same number of entries with the same types. (42, 'a') TUPLE(INTEGER, VARCHAR) UNION A union of multiple alternative data types, storing one of them in each value at... - https://man.mtool.work/duckdb/2.0/sql/data_types/overview.html
- Numeric Types 9559
- Fixed-Width Integer Types The types TINYINT , SMALLINT , INTEGER , BIGINT and HUGEINT store whole numbers, that is, numbers without fractional components, of various ranges. Attempts to store values outside of the allowed range will result
...in an error. The types UTINYINT , USMALLINT , UINTEGER , UBIGINT and UHUGEINT store whole unsigned numbers. Attempts to store negative numbers or...rage size, and performance. The SMALLINT type is generally only used if disk space is at a premium. The BIGINT and HUGEINT types are designed to be used when the range of the integer type is insufficient. Variable-Length Integers The previously mentio...ned integer types all have in common that the numbers in the minimum and maximum range all have the same storage size, UTINYINT is 1 byte, S... - https://man.mtool.work/duckdb/2.0/sql/data_types/numeric.html
- Types API 9502
- The DuckDBPyType class, duckdb.sqltypes.DuckDBPyType , represents one of the data types . Use DuckDBPyType to describe SQL types when declaring function parameters, return types or casts. Python types such as int are accepted too: int descr
...s BIGINT . Converting a data value such as 5 follows different rules; see Python Object Conversion . Converting from Other Types Wherever a DuckDBPyType is expected, any of the options listed below can be given instead. Python Built-Ins The table belo...w shows the mapping of Python Built-in types to DuckDB type. Built-in types DuckDB type bool BOOLEAN bytearray BLOB bytes BLOB float DOUBLE int BIGINT str VARCHAR NumP...y Scalar Types The table below shows the mapping of NumPy scalar types to DuckDB type. A NumPy dtype object does not convert: DuckDBPyTyp... - https://man.mtool.work/duckdb/2.0/clients/python/types.html
- Node.js Client (Neo) 8926
- 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
...rately as @duckdb/node-bindings . Roadmap Some features are not yet complete: Binding and appending the MAP and UNION data types Appending default values row-by-row User-defined types & functions Profiling info Table description APIs for Arrow See the...ion.disconnectSync(); or, equivalently: connection.closeSync(); Run SQL const result = await connection.run('from test_all_types()'); The SQL string may contain multiple statements separated by semicolons. In that case, all of the statements are execu...{ 'a': 'duck', 'b': 42, 'c': listValue([10, 11, 12]), }, { 'a': VARCHAR, 'b': INTEGER, 'c': LIST(INTEGER), }); Unspecified types will be inferred: const result = await connection.run('select $a, $b, $c', { 'a': 'duck', 'b': 42, 'c': listValue([10, 11,... - https://man.mtool.work/duckdb/2.0/clients/node_neo/overview.html
- Writing Tests 8485
- Development and Testing It is crucial that any new features that get added have correct tests that not only test the “happy path”, but also test edge cases and incorrect usage of the feature. In this section, we describe how DuckDB tests ar
...e from a given client. Functions for Generating Test Data DuckDB has built-in functions for generating test data. test_all_types Function The test_all_types table function generates a table whose columns correspond to types ( BOOL , TINYINT , etc.). T...he table has three rows encoding the minimum value, the maximum value, and the NULL value for each type. FROM test_all_types(); ┌─────────┬─────────┬──────────┬─────────────┬──────────────────────┬──────────────────────┬───┬──────────────────────┬...─────────────────────────────────────────────────────────────────────────────────────────────────────────────┘ test_vector_types Function The test_vector_types table function takes n arguments col1 , ..., coln and an optional BOOLEAN argument all_flat... - https://man.mtool.work/duckdb/2.0/dev/sqllogictest/writing_tests.html
- Excel Extension 8429
- The excel extension provides functions to format numbers per Excel's formatting rules by wrapping the i18npool library and to read/write Excel ( .xlsx ) files. However, please note that .xls files are not supported. Installing and Loading T
..._varchar BOOLEAN false Whether to treat empty cells as VARCHAR instead of DOUBLE when trying to automatically infer column types. SELECT * FROM read_xlsx('test.xlsx', header = true); a b 1.0 2.0 3.0 4.0 Alternatively, the COPY statement with the XLSX...format option can be used to import an Excel file into an existing table, in which case the types of the columns in the target table will be used to coerce the types of the cells in the Excel file. CREATE TABLE test (a D...ce that all cells in a column are of the same type, the excel extension has to do some guesswork to "infer" and decide the types of the columns when importing an Excel sheet. While almost all columns are inferred as either DOUBLE or VARCHAR , there ar... - https://man.mtool.work/duckdb/2.0/core_extensions/excel.html
- ODBC Extension 8237
- Please note that DuckDB also offers an ODBC client , which allows you to connect to DuckDB via ODBC from other applications. The odbc_scanner extension allows connecting to other databases (using their ODBC drivers ) and run queries with th
.../odbc_scanner/⟨7_character_commit_id⟩/v1.2.0/⟨platform⟩/odbc_scanner.duckdb_extension.gz'; Support Status of DBMS-Specific Types Tier 1: Oracle: types coverage status SQL Server: types coverage status DB2: types coverage status Tier 2: PostgreSQL: bas...ic types covered MySQL/MariaDB: basic types covered Firebird: types coverage status Tier 3: Snowflake: types coverage status ClickH...ouse: basic types covered Spark: basic types covered Arrow Flight SQL: basic types covered Installing unixODBC Driver Manager on Linux or ma... - https://man.mtool.work/duckdb/2.0/core_extensions/odbc/overview.html
- Hive Partitioning 7604
- Examples Read data from a Hive partitioned dataset: SELECT * FROM read_parquet('orders/*/*/*.parquet', hive_partitioning = true); Write a table to a Hive partitioned dataset: COPY orders TO 'orders' (FORMAT parquet, PARTITION_BY (year, mont
...tioning option of the reader function: SELECT * FROM read_parquet('orders/*/*/*.parquet', hive_partitioning = false); Hive Types hive_types is a way to specify the logical types of the hive partitions in a struct: SELECT * FROM read_parquet( 'dir/**/*....parquet', hive_partitioning = true, hive_types = {'release': 'DATE', 'orders': 'BIGINT'} ); hive_types will be auto-detected for the following types: DATE , TIMESTAMP an...d BIGINT . To switch off the auto-detection, the flag hive_types_autocast = 0 can be set. Writing Partitioned Files See the Partitioned Writes section.... - https://man.mtool.work/duckdb/2.0/data/partitioning/hive_partitioning.html
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