TableFunctionLayout (General SQL Parser Java Library Core 4.2.19 API)

Object
- gudusoft.gsqlparser.resolver2.namespace.TableFunctionLayout

```
public final class TableFunctionLayout
extends Object
```
The columns of a FROM item that a call generates (a built-in table function, UNNEST, a Hive-family LATERAL VIEW), and which of the call's arguments each one is computed from. One rule for every consumer: TableNamespace takes a function's column names from it, and TTable.getLateralColumnNames() and its siblings publish the whole layout to the SQL-LR producer (plan 09 slice 11).
A column's inputs are the indexes, in getArguments(), of the arguments whose values make its value ("0,1"); the empty string says the column is computed over the rows the call generates and has no value of an argument in it (an ordinal: WITH ORDINALITY, WITH OFFSET, FLATTEN's SEQ and INDEX, posexplode's position). getRowInputs() lists the arguments whose values decide how many rows the call generates. An argument that is in neither (a FLATTEN option) feeds nothing: the layout never says "every argument flows into every column".

A call whose columns the vendor fixes has a layout: an unqualified built-in of the vendor (myschema.flatten(...) is a user function that shares the name). So does a user table function the catalog declares before the call (declaredColumns(gudusoft.gsqlparser.stmt.TCreateFunctionStmt), recorded on the call by recordDeclared(gudusoft.gsqlparser.nodes.TTable, gudusoft.gsqlparser.sqlenv.TSQLEnv)): its names only, which arguments make them and decide its rows being its body's. Any other function, a call with a shape the rule below does not settle (STRING_SPLIT with a non-constant enable_ordinal), has none. A call whose rows are settled but not its columns (an UNNEST of several arrays without a column list naming one column per array) has a layout without names: its rows still come from its arrays.

Since:

4.2.17

Field Summary

Fields
Modifier and Type Field and Description

static String OVER_ROWS
The inputs of a column computed over the generated rows (an ordinal), with no argument value in it.

Fields
Modifier and Type	Field and Description
`static String`	`OVER_ROWS` The inputs of a column computed over the generated rows (an ordinal), with no argument value in it.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static List<String>`	`declaredColumns(TCreateFunctionStmt function)` The columns a CREATE FUNCTION declares its table result to have, in order: a `RETURNS TABLE (c ...)` or `RETURNS @t TABLE (c ...)` column list, else the output names of its query (SQL Server's inline `RETURN (SELECT ...)`, BigQuery's {@code CREATE TABLE FUNCTION ...
`List<TParseTreeNode>`	`getArguments()` The arguments, in order: the call's own expressions, or the arrays of an `UNNEST` (an expression, or the column name of BigQuery's and Presto's `UNNEST(t.arr)`).
`List<String>`	`getInputs()` Per column, the arguments whose values make it (`"0,1"`), or `OVER_ROWS`; null when the names are settled but the arguments are not (a FLATTEN call whose arguments the rule does not read).
`List<String>`	`getNames()` The column names, in order; an element is null for a column the vendor leaves without a name a query can use (BigQuery's element of an unaliased `UNNEST`).
`String`	`getRowInputs()` The arguments whose values decide the generated rows (`"0,1"`; empty when none).
`boolean`	`isClosed()` Whether the columns listed are all the call's columns: false when the element type of an array is not known (an `UNNEST` of a column may hold a STRUCT or ROW whose fields are columns of their own).
`static TableFunctionLayout`	`of(TTable table)` The layout of a FROM item, or null when the item is not a call whose columns or rows this rule settles.
`static void`	`recordDeclared(TTable table, TSQLEnv env)` Records on a function call in FROM the columns the catalog declares for the function it calls (a CREATE FUNCTION of the input registered before the call, or the catalog's metadata), so every consumer of the layout reads the columns resolver2 resolved the call with; nothing for a built-in this rule lays out, or an unknown function.
`static List<TParseTreeNode>`	`unnestArrays(TUnnestClause clause)` The arrays of an `UNNEST`, in order: its expressions, or the column names the legacy form keeps (`UNNEST(t.arr)` of BigQuery and Presto: a column list, no expression).

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - OVER_ROWS
```
public static final String OVER_ROWS
```
    The inputs of a column computed over the generated rows (an ordinal), with no argument value in it.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getNames
```
public List<String> getNames()
```
    The column names, in order; an element is null for a column the vendor leaves without a name a query can use (BigQuery's element of an unaliased UNNEST). Null when only the rows are settled (an UNNEST of several arrays without a column list for each): the call then has no column this rule names.
  - getInputs
```
public List<String> getInputs()
```
    Per column, the arguments whose values make it ("0,1"), or OVER_ROWS; null when the names are settled but the arguments are not (a FLATTEN call whose arguments the rule does not read).
  - getRowInputs
```
public String getRowInputs()
```
    The arguments whose values decide the generated rows ("0,1"; empty when none).
  - isClosed
```
public boolean isClosed()
```
    Whether the columns listed are all the call's columns: false when the element type of an array is not known (an UNNEST of a column may hold a STRUCT or ROW whose fields are columns of their own).
  - getArguments
```
public List<TParseTreeNode> getArguments()
```
    The arguments, in order: the call's own expressions, or the arrays of an UNNEST (an expression, or the column name of BigQuery's and Presto's UNNEST(t.arr)).
  - of
```
public static TableFunctionLayout of(TTable table)
```
    The layout of a FROM item, or null when the item is not a call whose columns or rows this rule settles. A layout whose getNames() is null settles the rows only.
  - declaredColumns
```
public static List<String> declaredColumns(TCreateFunctionStmt function)
```
    The columns a CREATE FUNCTION declares its table result to have, in order: a RETURNS TABLE (c ...) or RETURNS @t TABLE (c ...) column list, else the output names of its query (SQL Server's inline RETURN (SELECT ...), BigQuery's CREATE TABLE FUNCTION ... AS SELECT ...); null when it declares no table result or a column has no name (a wildcard, an expression without an alias). Registered with the function in the catalog; a call of it in FROM has these columns (recordDeclared(gudusoft.gsqlparser.nodes.TTable, gudusoft.gsqlparser.sqlenv.TSQLEnv)).
  - recordDeclared
```
public static void recordDeclared(TTable table,
                                  TSQLEnv env)
```
    Records on a function call in FROM the columns the catalog declares for the function it calls (a CREATE FUNCTION of the input registered before the call, or the catalog's metadata), so every consumer of the layout reads the columns resolver2 resolved the call with; nothing for a built-in this rule lays out, or an unknown function.
  - unnestArrays
```
public static List<TParseTreeNode> unnestArrays(TUnnestClause clause)
```
    The arrays of an UNNEST, in order: its expressions, or the column names the legacy form keeps (UNNEST(t.arr) of BigQuery and Presto: a column list, no expression).

Class TableFunctionLayout

Field Summary

Method Summary

Methods inherited from class Object

Field Detail

OVER_ROWS

Method Detail

getNames

getInputs

getRowInputs

isClosed

getArguments

of

declaredColumns

recordDeclared

unnestArrays