# wire.data.DataTable ## Properties A data table holds an array of objects in the `Rows` property much like the rows in a relational database table. Each property in the object has a column that stores meta data about the property in the `Columns` property. | Name | Type | Default | Description | | ------- | ----- | ------- | ------------------------------------------------------------------------------------------------------ | | Columns | array | \[ ] | Stores an array of column meta data about each property in the the list of objects stored in each row. | | Rows | array | \[ ] | Holds the raw list of objects in the data table. | Create a new data table by passing in an array of rows and an optional list of columns. If the columns aren't passed in, they will be created from the rows automatically. ```typescript let rows = [ { UserName: "apeters", FullName: "Amy Peters", Quota: 1000, Active: true}, { UserName: "jross", FullName: "John Ross", Quota: 1500, Active: true } ] let table = new wire.data.DataTable(rows); ``` ## Methods | Name | Description | | ---- | ----------------------------------------------------------------------------------------------------------------- | | cast | Static method that casts an object with the same data table properties into an instance of the `DataTable` class. | ## Select Methods Use the `select` method in order to select data from the data table. The `select` method can take an optional list of comma delimited fields to be selected. | Name | Description | | --------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | calc(function) | Creates a calculated column. As the `function` is evaluated, it will receive the current row, index position, and the list of all rows as delegate parameters. Visit [Working with DataTable Columns](/wirebootstrap/working-with-datatables/columns.md#calculated-columns) or [DataTable Columns](/wirebootstrap/reference/wire.data/wire.data.datatable/columns.md#addcolumn-methods) for more detail. | | column(column) | Select an individual `column` name. | | distinct | Return a distinct list of rows based on the columns being selected. | | nonEmpty | Return only rows that contain no null values. | | orderBy(column) | Return the list of rows sorted by `column`. | | top(N) | Return on the top `N` number of records. | | as(newName) | Change the name of the column selected from the `column` method to `newName`. | | format(format) | Format selected column using the specification in `format`. This can also be a custom function. | ### Select Aggregate Methods | Name | Description | | --------------------- | ------------------------------------------------------------------------------------------------ | | avg(column) | Aggregate the numeric `column` using an average or arithmetic mean. | | count(column) | Aggregate the numeric `column` by counting the rows. | | distinctCount(column) | Aggregate the numeric `column` using a discount count of the rows based on the selected columns. | | max(column) | Return the largest numeric value in the `column`. | | min(column) | Return the smallest numeric value in the `column`. | | sum(column) | Aggregate the numeric `column` by totaling all of its values. | Select the `UserName` column from the data table. Also select the `FullName` field but change its name to `DisplayName`. Aggregate the `Quota` column using a `sum` and format it to a whole number with no decimals which will include thousand separator commas. The result will automatically be grouped by `UserName` and `DisplayName`. ```typescript table.select("UserName") .column("FullName").as("DisplayName") .sum("Quota").format("N0"); ``` ## Filter Methods Start a filter chain using the `where` method. | Name | Description | | ------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | filter(function) | Use a custom function to filter the rows of the data table. As the `function` is evaluated, it will receive the current row, index position, and the list of all rows as delegate parameters. | | between(column, value1, value2) | Filter rows to those that have a `column` value that is between `value1` and `value2`. This comparison will handle numbers and dates and is case sensitive. It is also inclusive and will include of `value1` and `value2` if applicable. | | contains(column, expression) | Filter rows to those that contain a specific `expression` inside a `column`. A value will be included in this filter if any part of the value contains the `expression`. This comparison is case insensitive. | | eq(column, value) | Filter rows to those that have a `column` value that equals `value`. This comparison is case sensitive. | | in(column, values) | Filter rows to those that are contained inside the array of `values` in `column`. This comparison is case sensitive. | | ne(column, value) | Filter rows to those that have a `column` value that do not equal `value`. This comparison is case sensitive. | | starts(column, value) | Filter rows to those that start with a specific `expression` inside a `column`. This comparison is case insensitive. | Filter the data table to `UserName` equal to `apeters` but only if her `Quota` is greater than `800`. ```typescript table.select().where() .eq("UserName", "apeters") .filter((row, index, rows) => { return row.Quota > 800; }); ``` ## Evaluation Methods Once fields are selected and filtered, use the following methods to evaluate the resulting rows. | Name | Type | Description | | -------------- | ---------------- | ------------------------------------------------------------------------------------------------------------------------ | | count | number | Returns the number row in the result set. | | exists | boolean | Returns a true if any rows exist in the result set. Otherwise, returns false. | | first | object \| null | Returns the first row in the result set. If there are no rows, returns `null`. | | firstOrDefault | object | Returns the first row in the result set. If there are no rows, returns a row with values for each column set to `null`. | | rows | array | Returns all the rows in the result set. | | scaler | string \| number | Returns the first value in the first row. Assumes there is only one row and one column in the result set. | | table | DataTable | Creates a new data table from the result set. | The following creates a new data table with just the `UserName` field from the original data table. ```typescript let newTable = table.select("UserName").table(); ``` Visit [Working with DataTables](/wirebootstrap/working-with-datatables/datatables.md) for more details and examples on using data tables. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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