sql - Why does COUNT(*) multiply the results when there are several tables? -


I have found: 

  SELECT COUNT (*) to Table 1, Tab 2 , Table 3; Say that Tab 1 has 5 entries, Table 3 has 5 entries, and one in Tab 3, COUNT (*) is essentially 5 * 5 * 1 = 25. Is there any reason for this? Ideally, I want the total line number from all the 3 tables without using multiple from the statement   
 
 
  Select number (*) to Table 1, Tab 2, Tab 3;  
 
 does a  cross join . It corresponds to each record in  TABLE1  from each record in  TABLE2 , then matches the eash result with each record in  TABLE3  For example if there were 4 records containing <3> record and  TABLE4  in 2 records,  TABLE2  in  TABLE1 , you would have  2 x 3 x 4 = 24 was received> as your result.  
 You will need to use the subkey to calculate from each table:  
  SELECT (SELECT COUNT (*) to TABLE1), (SELECT COUNT (* ) From tab 2), (tab number from selection number (*) 3); TABLE1 union from all SELECT COUNT (*) to tab2 union ALL SELECTED COUNT (*) to TABLE3  
 
 OR 
 
  SELECT COUNT (*)  
 
 
 
  to get the result as a record instead of columns

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