Checks whether a specified table exists in MaxCompute.
Syntax
boolean table_exists(string <table_name>)Parameters
table_name: required. The name of the table to check. This parameter is of the STRING type.
-
To check a table in a different project, use the format
<project_name>.<table_name>(for example,my_proj.my_table). -
If you omit the project name, the function checks the current project.
Return value
Returns a BOOLEAN value:
-
True: the specified table exists. -
False: the specified table does not exist.
Usage notes
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The function checks tables in the current project by default. To check a table in another project, prefix the table name with the project name.
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Use this function in a
SELECTexpression or as part of a conditional expression such asIF().
Examples
The following example uses table_exists inside an IF() expression to select from two different columns based on whether table abd exists. If the table exists, col1 is returned; otherwise, col2 from table src is returned. This pattern lets you write queries that are resilient to optional tables.
select if(table_exists('abd'), col1, col2) from src;Related functions
For more information, see Other functions.