Category: Database

SQL Data types,”char(size) Fixed-length character string. Size is specified in parenthesis. Max 255 bytes.varchar(size) Variable-length character string. Max size is specified in parenthesis.number(size) Number value with a max number of column digits specified in parenthesis.date Date valuenumber(size,d) Number value with a maximum number of digits of “”size”” total

Database

Average Rating 0 out of 5 stars. 0 votes.You must log in to submit a review.SQL Data types,”char(size) Fixed-length character[…]

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Constraint (SQL),”A rule associated with a column that the data entered into that column must follow. For example, a “”unique”” constraint specifies that no two records can have the same value in a particular column. They must all be unique. The other two most popular constraints are “”not null”” which specifies that a column can’t be left blank

Database

Average Rating 0 out of 5 stars. 0 votes.You must log in to submit a review.Constraint (SQL),”A rule associated with[…]

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Insert (SQL),”The insert statement is used to insert or add a row of data into the table.General: insert into “”tablename”” (first_column,…last_column) values (first_value,…last_value);ex. insert into employee (first, last, age, address, city, state) values (‘Luke’, ‘Duke’, 45, ‘2130 Boars Nest’, ‘Hazard Co’

Database

Average Rating 0 out of 5 stars. 0 votes.You must log in to submit a review.Insert (SQL),”The insert statement is[…]

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Update (SQL),”Update a row in a table.General: update “”tablename””set “”columnname”” = “”newvalue”” [,””nextcolumn”” = “”newvalue2″”…]where “”columnname”” OPERATOR “”value”” [and|or “”column”” OPERATOR “”value””]; [] = optionalex. update phone_book set area_code = 623 where prefix = 979;update phone_book set last_name = ‘Smith’, prefix=555

Database

Average Rating 0 out of 5 stars. 0 votes.You must log in to submit a review.Update (SQL),”Update a row in[…]

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