[data.read]

data.read is a slot in the data namespace, in Hyperlambda, the language of Magic Cloud. Selects rows from the current open database connection; returns all columns unless [columns] is supplied and limits to 25 rows unless [limit] is supplied.

Returns: Resolves to matching rows as child nodes
Scope: requires data.connection - Requires an open database connection created by [data.connect]

Arguments

Required arguments come first, then the optional ones in the order they are declared.

Argument	Type	Required	Description
`[table]`	string	yes	Table name to use in the SQL statement.
`[table]` / `[as]`	string	no	Optional table alias.
`[table]` / `[join]`	string	no	Joined table name. Can be repeated.
`[table]` / `[join]` / `[on]`	lambda	yes	Join predicate tree comparing columns (AND-only at the schema level; the SQL builder still accepts hand-written [or] for legacy code).
`[table]` / `[join]` / `[on]` / `[and]`	lambda	yes	Boolean AND group.
`[table]` / `[join]` / `[on]` / `[and]` / any node name	object	yes	Join predicate: LHS is a column-with-operator suffix, RHS is the joined-side column reference (leaf-only — value-list children are a WHERE-clause feature, not meaningful in JOIN ON).
`[table]` / `[join]` / `[type]`	string	no	Join type: inner, left, right, or full. Default: `inner`.
`[table]` / `[join]` / `[as]`	string	no	Optional joined table alias.
`[database-type]`	string	no	Database adapter to use instead of the configured default.
`[generate]`	bool	no	Whether to only generate SQL and parameter nodes instead of executing it. Default: `false`.
`[distinct]`	bool	no	Removes duplicate rows from the result set when true. Default: `false`.
`[columns]`	lambda	no	Columns or aggregate expressions to select; omitted or empty means all columns.
`[columns]` / any node name	string	no	Column name or aggregate expression; optional [as] child declares an alias. Can be repeated.
`[columns]` / any node name / `[as]`	string	no	Column alias.
`[where]`	lambda	no	Optional boolean predicate tree.
`[where]` / `[and]`	lambda	no	Boolean AND group.
`[where]` / `[and]` / any node name	object	yes	Column condition; suffix the name with .eq, .neq, .gt, .gte, .lt, .lte, .like, .ilike, or .in to select an operator. Can be repeated.
`[where]` / `[and]` / any node name / unnamed child node	object	no	Value item used by operators such as .in.
`[where]` / `[and]` / `[or]`	lambda	no	Boolean OR group. Can be repeated.
`[where]` / `[and]` / `[or]` / any node name	object	yes	Column condition; suffix the name with .eq, .neq, .gt, .gte, .lt, .lte, .like, .ilike, or .in to select an operator. Can be repeated.
`[where]` / `[and]` / `[or]` / any node name / unnamed child node	object	no	Value item used by operators such as .in.
`[where]` / `[or]`	lambda	no	Boolean OR group.
`[where]` / `[or]` / any node name	object	yes	Column condition; suffix the name with .eq, .neq, .gt, .gte, .lt, .lte, .like, .ilike, or .in to select an operator. Can be repeated.
`[where]` / `[or]` / any node name / unnamed child node	object	no	Value item used by operators such as .in.
`[where]` / `[or]` / `[and]`	lambda	no	Boolean AND group. Can be repeated.
`[where]` / `[or]` / `[and]` / any node name	object	yes	Column condition; suffix the name with .eq, .neq, .gt, .gte, .lt, .lte, .like, .ilike, or .in to select an operator. Can be repeated.
`[where]` / `[or]` / `[and]` / any node name / unnamed child node	object	no	Value item used by operators such as .in.
`[group]`	lambda	no	Columns or aggregate expressions to group by.
`[group]` / any node name	string	no	Column name or aggregate expression. Can be repeated.
`[order]`	string	no	Column, comma-separated columns, or aggregate expression to order by. Can be repeated.
`[order]` / `[direction]`	string	no	Order direction for this specific order node. Default: `asc`.
`[limit]`	long	no	Maximum number of rows to return; omitted defaults to 25 and -1 suppresses the generated limit clause. Default: `25`.
`[offset]`	long	no	Number of rows to skip. Default: `0`.

Nodes nested deeper than 6 levels, and nodes that repeat one of their own ancestors, are not listed. The JSON declaration below has all of them.

Returned nodes

Node	Type	Required	Description
unnamed child node	lambda	no	One row returned by the read; child nodes carry the selected column values, with each child’s name being the column name or alias from the SELECT statement. Can be repeated.
unnamed child node / any node name	string	no	Column value; child name is the column name (or alias) declared in the read. Can be repeated.

JSON declaration

This is the complete declaration of data.read, as the running system describes it. It is also published as slot.json.

JSON declaration (loads when opened)

← data.execute

all data.* slots

data.scalar →