Symbol coords function

If SMILES is used to store molecular structures in a relational database management system(RDBMS), it may be necessary to extract the symbol and bond information for some client programs that expect a connection table. The smiles to symbol and smiles to bonds function shown in the next sections allow the symbol and bond information in a SMILES to be extracted as an array. Some client programs may prefer to process this information in rows, as if they were records in a file. The following plpgsql functions can be used to present the array elements as rows. Two functions are shown ctable (connection table) and symbol coords. The symbol coords function requires an array of coordinates in addition to the symbols. 

Create or Replace Function symbol coords(text) Returns Setof Record As EOSQL ... 

These functions are called with a string argument. This argument is an SQL statement that is expected to provide the required information. For ctable, this is an array of bonds. For symbol coords, these are an array of symbols and an array of coordinates for each atom. 

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