Interface: Table\<T>
A LanceDB Table is the collection of Records. Each Record has one or more vector fields.
Type parameters
| Name | Type |
|---|---|
T | number[] |
Implemented by
Table of contents
Properties
- add
- countRows
- createIndex
- createScalarIndex
- delete
- indexStats
- listIndices
- mergeInsert
- name
- overwrite
- schema
- search
- update
Methods
Properties
add
•add: (data:Table\<any> |Record\<string,unknown>[]) =>Promise\<number>
Type declaration
▸ (data):Promise\<number>
Insert records into this Table.
Parameters
| Name | Type | Description |
|---|---|---|
data | Table\<any> |Record\<string,unknown>[] | Records to be inserted into the Table |
Returns
Promise\<number>
The number of rows added to the table
Defined in
countRows
•countRows: (filter?:string) =>Promise\<number>
Type declaration
▸ (filter?):Promise\<number>
Returns the number of rows in this table.
Parameters
| Name | Type |
|---|---|
filter? | string |
Returns
Promise\<number>
Defined in
createIndex
•createIndex: (indexParams:IvfPQIndexConfig) =>Promise\<any>
Type declaration
▸ (indexParams):Promise\<any>
Create an ANN index on this Table vector index.
Parameters
| Name | Type | Description |
|---|---|---|
indexParams | IvfPQIndexConfig | The parameters of this Index, |
Returns
Promise\<any>
See
VectorIndexParams.
Defined in
createScalarIndex
•createScalarIndex: (column:string,replace?:boolean) =>Promise\<void>
Type declaration
▸ (column,replace?):Promise\<void>
Create a scalar index on this Table for the given column
Parameters
| Name | Type | Description |
|---|---|---|
column | string | The column to index |
replace? | boolean | If false, fail if an index already exists on the column it is always set to true for remote connections Scalar indices, like vector indices, can be used to speed up scans. A scalar index can speed up scans that contain filter expressions on the indexed column. For example, the following scan will be faster if the columnmy_col has a scalar index:ts const con = await lancedb.connect('./.lancedb'); const table = await con.openTable('images'); const results = await table.where('my_col = 7').execute(); Scalar indices can also speed up scans containing a vector search and a prefilter:ts const con = await lancedb.connect('././lancedb'); const table = await con.openTable('images'); const results = await table.search([1.0, 2.0]).where('my_col != 7').prefilter(true); Scalar indices can only speed up scans for basic filters using equality, comparison, range (e.g.my_col BETWEEN 0 AND 100), and set membership (e.g.my_col IN (0, 1, 2)) Scalar indices can be used if the filter contains multiple indexed columns and the filter criteria are AND'd or OR'd together (e.g.my_col < 0 AND other_col> 100) Scalar indices may be used if the filter contains non-indexed columns but, depending on the structure of the filter, they may not be usable. For example, if the columnnot_indexed does not have a scalar index then the filtermy_col = 0 OR not_indexed = 1 will not be able to use any scalar index onmy_col. |
Returns
Promise\<void>
Examples
constcon=awaitlancedb.connect('././lancedb')consttable=awaitcon.openTable('images')awaittable.createScalarIndex('my_col')Defined in
delete
•delete: (filter:string) =>Promise\<void>
Type declaration
▸ (filter):Promise\<void>
Delete rows from this table.
This can be used to delete a single row, many rows, all rows, orsometimes no rows (if your predicate matches nothing).
Parameters
| Name | Type | Description |
|---|---|---|
filter | string | A filter in the same format used by a sql WHERE clause. The filter must not be empty. |
Returns
Promise\<void>
Examples
constcon=awaitlancedb.connect("./.lancedb")constdata=[{id:1,vector:[1,2]},{id:2,vector:[3,4]},{id:3,vector:[5,6]},];consttbl=awaitcon.createTable("my_table",data)awaittbl.delete("id = 2")awaittbl.countRows()// Returns 2If you have a list of values to delete, you can combine them into astringified list and use theIN operator:
constto_remove=[1,5];awaittbl.delete(`id IN (${to_remove.join(",")})`)awaittbl.countRows()// Returns 1Defined in
indexStats
•indexStats: (indexName:string) =>Promise\<IndexStats>
Type declaration
▸ (indexName):Promise\<IndexStats>
Get statistics about an index.
Parameters
| Name | Type |
|---|---|
indexName | string |
Returns
Promise\<IndexStats>
Defined in
listIndices
•listIndices: () =>Promise\<VectorIndex[]>
Type declaration
▸ ():Promise\<VectorIndex[]>
List the indicies on this table.
Returns
Promise\<VectorIndex[]>
Defined in
mergeInsert
•mergeInsert: (on:string,data:Table\<any> |Record\<string,unknown>[],args:MergeInsertArgs) =>Promise\<void>
Type declaration
▸ (on,data,args):Promise\<void>
Runs a "merge insert" operation on the table
This operation can add rows, update rows, and remove rows all in a singletransaction. It is a very generic tool that can be used to createbehaviors like "insert if not exists", "update or insert (i.e. upsert)",or even replace a portion of existing data with new data (e.g. replaceall data where month="january")
The merge insert operation works by combining new data from asource table with existing data in atarget table by using ajoin. There are three categories of records.
"Matched" records are records that exist in both the source table andthe target table. "Not matched" records exist only in the source table(e.g. these are new data) "Not matched by source" records exist onlyin the target table (this is old data)
The MergeInsertArgs can be used to customize what should happen foreach category of data.
Please note that the data may appear to be reordered as part of thisoperation. This is because updated rows will be deleted from thedataset and then reinserted at the end with the new values.
Parameters
| Name | Type | Description |
|---|---|---|
on | string | a column to join on. This is how records from the source table and target table are matched. |
data | Table\<any> |Record\<string,unknown>[] | the new data to insert |
args | MergeInsertArgs | parameters controlling how the operation should behave |
Returns
Promise\<void>
Defined in
name
•name:string
Defined in
overwrite
•overwrite: (data:Table\<any> |Record\<string,unknown>[]) =>Promise\<number>
Type declaration
▸ (data):Promise\<number>
Insert records into this Table, replacing its contents.
Parameters
| Name | Type | Description |
|---|---|---|
data | Table\<any> |Record\<string,unknown>[] | Records to be inserted into the Table |
Returns
Promise\<number>
The number of rows added to the table
Defined in
schema
•schema:Promise\<Schema\<any>>
Defined in
search
•search: (query:T) =>Query\<T>
Type declaration
▸ (query):Query\<T>
Creates a search query to find the nearest neighbors of the given search term
Parameters
| Name | Type | Description |
|---|---|---|
query | T | The query search term |
Returns
Query\<T>
Defined in
update
•update: (args:UpdateArgs |UpdateSqlArgs) =>Promise\<void>
Type declaration
▸ (args):Promise\<void>
Update rows in this table.
This can be used to update a single row, many rows, all rows, orsometimes no rows (if your predicate matches nothing).
Parameters
| Name | Type | Description |
|---|---|---|
args | UpdateArgs |UpdateSqlArgs | seeUpdateArgs andUpdateSqlArgs for more details |
Returns
Promise\<void>
Examples
constcon=awaitlancedb.connect("./.lancedb")constdata=[{id:1,vector:[3,3],name:'Ye'},{id:2,vector:[4,4],name:'Mike'},];consttbl=awaitcon.createTable("my_table",data)awaittbl.update({where:"id = 2",values:{vector:[2,2],name:"Michael"},})letresults=awaittbl.search([1,1]).execute();// Returns [// {id: 2, vector: [2, 2], name: 'Michael'}// {id: 1, vector: [3, 3], name: 'Ye'}// ]Defined in
Methods
addColumns
▸addColumns(newColumnTransforms):Promise\<void>
Add new columns with defined values.
Parameters
| Name | Type | Description |
|---|---|---|
newColumnTransforms | {name:string ;valueSql:string }[] | pairs of column names and the SQL expression to use to calculate the value of the new column. These expressions will be evaluated for each row in the table, and can reference existing columns in the table. |
Returns
Promise\<void>
Defined in
alterColumns
▸alterColumns(columnAlterations):Promise\<void>
Alter the name or nullability of columns.
Parameters
| Name | Type | Description |
|---|---|---|
columnAlterations | ColumnAlteration[] | One or more alterations to apply to columns. |
Returns
Promise\<void>
Defined in
dropColumns
▸dropColumns(columnNames):Promise\<void>
Drop one or more columns from the dataset
This is a metadata-only operation and does not remove the data from theunderlying storage. In order to remove the data, you must subsequentlycallcompact_files to rewrite the data without the removed columns andthen callcleanup_files to remove the old files.
Parameters
| Name | Type | Description |
|---|---|---|
columnNames | string[] | The names of the columns to drop. These can be nested column references (e.g. "a.b.c") or top-level column names (e.g. "a"). |
Returns
Promise\<void>
Defined in
dropIndex
▸dropIndex(indexName):Promise\<void>
Drop an index from the table
Parameters
| Name | Type | Description |
|---|---|---|
indexName | string | The name of the index to drop |
Returns
Promise\<void>
Defined in
filter
▸filter(value):Query\<T>
Parameters
| Name | Type |
|---|---|
value | string |
Returns
Query\<T>
Defined in
withMiddleware
▸withMiddleware(middleware):Table\<T>
Instrument the behavior of this Table with middleware.
The middleware will be called in the order they are added.
Currently this functionality is only supported for remote tables.
Parameters
| Name | Type |
|---|---|
middleware | HttpMiddleware |
Returns
Table\<T>
- this Table instrumented by the passed middleware