Results of 1 - 10 of about 11 for evaluate (0.002 sec.)
- Logical Operators 14332
- The following logical operators are available: AND , OR and NOT . SQL uses a three-valued logic system with true , false and NULL . Note that logical operators involving NULL do not always evaluate to NULL . For example, NULL AND false will
...evaluate to false , and NULL OR true will evaluate to true . Below are the complete truth tables. Binary Operators: AND and OR a b... - https://man.mtool.work/duckdb/2.0/sql/expressions/logical_operators.html
- Subqueries 9388
- 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
...NY and SOME . The quantifiers ANY and SOME are equivalent. ALL The ALL quantifier specifies that the comparison as a whole evaluates to true when the individual comparison results of the expression at the left hand side of the comparison operator with ea...ch of the values from the subquery at the right hand side of the comparison operator all evaluate to true : SELECT 6 <= ALL (SELECT grade FROM grades) AS adequate; returns: adequate true because 6 is less than or equal t...rns excellent false because 8 is not greater than or equal to the subquery result 9. And thus, because not all comparisons evaluate to true , >= ALL as a whole evaluates to false . ANY The ANY quantifier specifies that the comparison as a whole evaluates... - https://man.mtool.work/duckdb/2.0/sql/expressions/subqueries.html
- Overview of DuckDB Internals 8784
- Tip For a detailed explanation of DuckDB internals, see the Design and Implementation of DuckDB Internals ("DiDi") library entry. On this page is a brief description of the internals of the DuckDB engine. Parser The parser converts a query
...es filters over equivalency sets. Also prunes subtrees that are guaranteed to be empty (because of filters that statically evaluate to false). Join Order Optimizer : Reorders joins using dynamic programming. Specifically, the DPhyp algorithm from the pap... - https://man.mtool.work/duckdb/2.0/internals/overview.html
- Comparisons 8784
- Comparison Operators The table below shows the standard comparison operators. Whenever either of the input arguments is NULL , the output of the comparison is NULL . Operator Description Example Result < less than 2 < 3 true > greater than
...eral programming languages but are often not compatible with PostgreSQL's behavior. For example, the following expressions evaluate and return true in DuckDB but fail in PostgreSQL. SELECT 1 = true; SELECT 1 = '1.1'; It is not possible to enforce stricte... - https://man.mtool.work/duckdb/2.0/sql/expressions/comparison_operators.html
- Reading Faulty CSV Files 8179
- CSV files can come in all shapes and forms, with some presenting many errors that make the process of cleanly reading them inherently difficult. To help users read these files, DuckDB supports detailed error messages, the ability to skip fa
...ss and throw the error to the user. These errors are designed to provide as much information as possible to allow users to evaluate them directly in their CSV file. This is an example for a full error message: Conversion Error: CSV Error on Line: 5648 Or... - https://man.mtool.work/duckdb/2.0/data/csv/reading_faulty_csv_files.html
- Numeric Types 8179
- 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
...the floating-point data types may be more appropriate. However, if you use the results for anything important, you should evaluate your implementation carefully for corner cases (ranges, infinities, underflows, invalid operations) that may be handled di... - https://man.mtool.work/duckdb/2.0/sql/data_types/numeric.html
- Lambda Functions 8179
- DuckDB lambda functions (a.k.a. 'lambdas' or 'lambda expressions') are expressions that define an inline anonymous function. Lambdas are passed as argument to certain list functions , which evaluate the passed lambda expression against its
...eturn value. Lambdas may also be used in the COLUMNS clause . In that context, the lambda function acts as a filter: if it evaluates to true , the column is retained, and discarded otherwise. COLUMNS -clause lambdas have a mandatory parameter that receiv... - https://man.mtool.work/duckdb/2.0/sql/functions/lambda.html
- ATTACH and DETACH Statements 8037
- DuckDB allows attaching to and detaching from database files. Examples Attach the database file.db with the alias inferred from the name ( file ): ATTACH 'file.db'; Attach the database file.db with an explicit alias ( file_db ): ATTACH 'fil
...g literal. The database path and the option values can be arbitrary scalar expressions rather than string literals. DuckDB evaluates these expressions while binding the ATTACH statement, so you can build them from variables , environment variables or str...tenv() , which is available in the CLI client only: ATTACH getenv('DATABASE_PATH') AS env_db; The path expression must not evaluate to NULL . Options Zero or more copy options may be provided within parentheses following the ATTACH statement. Parameter v... - https://man.mtool.work/duckdb/2.0/sql/statements/attach.html
- CREATE MACRO Statement 8037
- The CREATE MACRO statement defines a named, callable SQL expression as a database schema object. Macros may declare parameters, which can be referenced by its expression. Once a macro is created, it may be called by referencing its name and
...by passing values to its parameters; this causes its expression to be evaluated, yielding a value. Depending on the macro type, the value may be scalar, or a TABLE value. The CREATE FUNCTION statement...f Macros The contexts where a particular macro may be called depends on the data type of its result value: * Scalar macros evaluate to a scalar value. For scalar macros, the expression can either be a simple expression, or a scalar subquery. * Table macr...operator := , followed by the expression that is to be used as default value. The default value expression is in principle evaluated at definition-time - NOT at run-time. (There are a few exceptions, like CURRENT_SCHEMA . But it's best not to rely on tha... - https://man.mtool.work/duckdb/2.0/sql/statements/create_macro.html
- Node.js Client (Neo) 7895
- 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
..._MS timestampMillisValue TIMESTAMP_NS timestampNanosValue UNION unionValue UUID uuidValue Stream Results Streaming results evaluate lazily when rows are read. const result = await connection.stream('from range(10_000)'); Inspect Result Metadata Get colum... - https://man.mtool.work/duckdb/2.0/clients/node_neo/overview.html
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