Smiles to bonds function

The smiles to symbols and smile to bonds functions return arrays of values. In the sample output above, the smiles to bonds output has been truncated for easier viewing. Some client programs may expect this information as separate rows, as if they were records in a file. These arrays may be cast into that form by using a plpgsql function that returns elements of an array as rows. This is shown in the next section. 

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. 

Although SMILES is an entirely equivalent way of storing a connection table of atoms and bonds, it is sometimes desirable to create a traditional connection table, for example, when an external program requires it. The extension functions smiles to symbols and smiles to bonds accept a SMILES string and produce an array of either symbols or bonds. These are discussed in a later section of this chapter. Several implementations of these functions are shown in the Appendix. 

Create Or Replace Function frowns.smiles to bonds(smi Text) Returns... 

Create Or Replace Function openbabel.smiles to bonds(smi Text) Returns Integer ] As EOPY import openbabel obc = openbabel.OBConversionO mol = openbabel.OBMol() obc.SetlnAndOutFormats("smi", "mol") if obc.Readstring(mol, smi) bonds = []... 

It would be possible to create tables using columns to store the atomic symbols and bond information found in molecular structure files, reflecting the column style format of the file itself. Instead, a SMILES representation of this valence bond information is preferred. SMILES is a compact text string containing the same information as the columns of atom symbols and bonds. It can also be used directly in the search functions described in earlier chapters. It is desirable to parse the molecular properties in molecular structure files in order to store them in data columns for possible searching... 

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