What is SQL?
Structured Query Language (SQL) is a set of defined expressions and syntax used to query and manipulate data in relational database management systems (RDBMS).
The American National Standards Institute (ANSI) defines a standard for SQL. Most RDBMSs use that standard and have extended it, making SQL syntax across different RDBMSs slightly different from one another.
In the context of the geodatabase, SQL can be used to access, create, and update simple data; in other words, data that does not participate in any geodatabase functionality such as networks, topology, terrains, parcel fabrics, schematics, relationship classes, geodatabase domains, or geodatabase replication.